diff --git a/assets/game_assets/assets_audio.map b/assets/game_assets/assets_audio.map
index 4462a86a17bbb04460a30b2d434280ebda97afa2..572a158bda8d86be819bed8f88992b85f61ffd2a 100644
--- a/assets/game_assets/assets_audio.map
+++ b/assets/game_assets/assets_audio.map
@@ -1,4 +1,2 @@
 audio: = audio/*.opus
-
-cfg:sound_effects = settings/sound_effects.json
-
+music: = music/*.opus
diff --git a/assets/game_assets/audio/Finish_01.ogg b/assets/game_assets/audio/Finish_01.ogg
deleted file mode 100644
index 00e56fb39afba6f494a01cc89870602c4ce9de13..0000000000000000000000000000000000000000
Binary files a/assets/game_assets/audio/Finish_01.ogg and /dev/null differ
diff --git a/assets/game_assets/audio/Finish_01.opus b/assets/game_assets/audio/Finish_01.opus
new file mode 100644
index 0000000000000000000000000000000000000000..a611d875b00429363d99c5d75a71af8abb7f7cf0
--- /dev/null
+++ b/assets/game_assets/audio/Finish_01.opus
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f4b081c18b8fd488aae71fc5a04af82c93ab0fb2bf554ad0d74605d11b64aac8
+size 92030
diff --git a/assets/game_assets/audio/beat.opus b/assets/game_assets/audio/beat.opus
new file mode 100644
index 0000000000000000000000000000000000000000..969b98db0591c9edb8b06f89f92351726af71097
--- /dev/null
+++ b/assets/game_assets/audio/beat.opus
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7b615bd2935ccefe3fa5f61110bbe037fb1ed29448c296161d6d936a6e89ae36
+size 12568
diff --git a/assets/game_assets/music/pulse.opus b/assets/game_assets/music/pulse.opus
new file mode 100644
index 0000000000000000000000000000000000000000..8dba48b62e753ac0aa93a11288ec68efd68c0c17
--- /dev/null
+++ b/assets/game_assets/music/pulse.opus
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:cdf9d010bcf91fa165cbd3b5d07d415eeeb8957255ea5362b8472da4fbc13559
+size 2087114
diff --git a/assets/game_assets/settings/gui.json b/assets/game_assets/settings/gui.json
index 77eafef25357d6ae431a07a425d83f6e2f0f4dc4..41d192d1adaa704ea1e3c174c6a0b56567fd1f1a 100644
--- a/assets/game_assets/settings/gui.json
+++ b/assets/game_assets/settings/gui.json
@@ -1,9 +1,24 @@
 {
 	"fonts": [
 		{
-			"id"   : "default",
-			"aid"  : "font:ui/RobotoCondensed-Regular.ttf",
-			"size" : 20
+			"id": "default",
+			"aid": "font:ui/blanka-regular.otf",
+			"size": 30
+		},
+		{
+			"id": "heading",
+			"aid": "font:ui/blanka-regular.otf",
+			"size": 70
+		},
+		{
+			"id": "sub_heading",
+			"aid": "font:ui/blanka-regular.otf",
+			"size": 50
+		},
+		{
+			"id": "huge",
+			"aid": "font:ui/blanka-regular.otf",
+			"size": 300
 		}
 	]
-}
\ No newline at end of file
+}
diff --git a/assets/game_assets/ui/blanka-regular.otf b/assets/game_assets/ui/blanka-regular.otf
new file mode 100644
index 0000000000000000000000000000000000000000..60b18d7816c9ea5635f8c276851970e575b5f953
Binary files /dev/null and b/assets/game_assets/ui/blanka-regular.otf differ
diff --git a/src/game_engine.cpp b/src/game_engine.cpp
index f42a43caa0a621c14fb6d72698c15fb5aee2aa81..0c7c67a256c01e0ce23ed1bac8fb3206f15622df 100644
--- a/src/game_engine.cpp
+++ b/src/game_engine.cpp
@@ -20,6 +20,8 @@
 #include <mirrage/renderer/pass/tone_mapping_pass.hpp>
 #include <mirrage/renderer/pass/transparent_pass.hpp>
 
+#include <sinks/sdl_sink.hpp>
+
 
 namespace phase_shifter {
 	using namespace mirrage;
@@ -61,6 +63,10 @@ namespace phase_shifter {
 	{
 		util::erase_fast(_render_pass_mask, renderer::render_pass_id_of<renderer::Gui_pass_factory>());
 		util::erase_fast(_render_pass_mask, renderer::render_pass_id_of<renderer::Clear_pass_factory>());
+
+		eam::settings setting{{16, true, false, false}, 2, 48000, 1024};
+		_audio.set_sink<eam::sdl_sink>(setting);
+		_audio.set_master_volume(35);
 	}
 
 	Game_engine::~Game_engine()
diff --git a/src/game_engine.hpp b/src/game_engine.hpp
index cd38361f0ecc6335453343f581a09b45c53bba0b..9fc48087ccfbcb68dfab938103ae8f5031b22d86 100644
--- a/src/game_engine.hpp
+++ b/src/game_engine.hpp
@@ -14,11 +14,13 @@
 #include <mirrage/gui/debug_ui.hpp>
 #include <mirrage/utils/maybe.hpp>
 
+#include <audio.hpp>
+
 
 namespace mirrage::renderer {
 	class Deferred_renderer_factory;
 }
-	
+
 namespace phase_shifter {
 
 	class Game_engine : public mirrage::Engine {
@@ -37,6 +39,11 @@ namespace phase_shifter {
 		auto renderer_factory() noexcept -> auto& { return *_renderer_factory; }
 		auto global_render() noexcept -> auto& { return *_global_render; }
 		auto render_pass_mask() noexcept -> auto& { return _render_pass_mask; }
+		auto audio() noexcept -> auto& { return _audio; }
+		auto audio_latency() const noexcept { return _audio_latency; }
+		auto audio_latency(float latency) noexcept { _audio_latency = latency; }
+		auto video_latency() const noexcept { return _video_latency; }
+		auto video_latency(float latency) noexcept { _video_latency = latency; }
 
 	  protected:
 		void _on_post_frame(mirrage::util::Time) override;
@@ -46,6 +53,9 @@ namespace phase_shifter {
 		std::unique_ptr<mirrage::renderer::Deferred_renderer_factory> _renderer_factory;
 		std::unique_ptr<mirrage::renderer::Deferred_renderer>         _global_render;
 		mirrage::renderer::Render_pass_mask                           _render_pass_mask;
-	};
-	
-} // namespace seapp
+		eam::audio                                                    _audio;
+		float                                                         _audio_latency = 0.f;
+		float                                                         _video_latency = 0.f;
+	}; // namespace phase_shifter
+
+} // namespace phase_shifter
diff --git a/src/meta_system.cpp b/src/meta_system.cpp
index 141a282dc03dab12cb1af630bfbb12565c3dc06b..706b442b606f2641bf914a86719b23c21513d881 100644
--- a/src/meta_system.cpp
+++ b/src/meta_system.cpp
@@ -32,10 +32,9 @@ namespace phase_shifter {
 
 	Meta_system::Meta_system(Game_engine& engine)
 	  : _entities(engine.assets(), this)
-	  , _audio()
 	  , _renderer(engine.renderer_factory().create_renderer(_entities, engine.render_pass_mask()))
 	  , _model_loading(std::make_unique<renderer::Loading_system>(_entities, engine.assets()))
-	  , _sound_manager(std::make_unique<audio::Sound_manager>(_audio, engine.bus(), engine.assets()))
+	  , _sound_manager(std::make_unique<audio::Sound_manager>(engine.audio(), engine.bus(), engine.assets()))
 	  , _beat_system(std::make_unique<gameplay::Beat_system>(engine.bus(), engine.assets()))
 	  , _level_system(std::make_unique<level::Level_system>(_entities, engine.assets()))
 	  , _movement_system(std::make_unique<gameplay::Movement_system>(
@@ -59,9 +58,6 @@ namespace phase_shifter {
 		//s.scene_luminance_override = 300.f;
 		//_renderer->settings(s, false);
 
-		eam::settings setting{{16, true, false, false}, 2, 48000, 1024};
-		_audio.set_sink<eam::sdl_sink>(setting);
-		_audio.set_master_volume(35);
 		/*auto bg_music =
 		        engine.assets().load<std::shared_ptr<eam::opus>>("audio:bg_music_01"_aid).get_blocking();
 		auto bg_context = _audio.generate_context(bg_music);
@@ -93,29 +89,32 @@ namespace phase_shifter {
 				LOG(plog::info) << "Renderer Memory usage: " << msg.str();
 			}
 		});
-
 		_level_system->load("dummy");
 
-		entities()
-		        .entity_builder("basic_enemy")
-		        .position({20, 0, 15})
-		        .post_create([=](auto entity) {
-			        entity.process([&](gameplay::Fixed_path_comp& fixed_path) { fixed_path.update_path({}); });
-			        entity.process([&](gameplay::Shooting_comp& shooting) { 
-						shooting.set_patterns({gameplay::Bulletpattern({{0, 0}})});
-					});
-				})
-		        .create();
+		auto bg_music = engine.assets().load<std::shared_ptr<eam::opus>>("music:pulse"_aid).get_blocking();
+		_music        = engine.audio().generate_context_ptr(bg_music);
+		_music->get_object()->set_loops(-1);
+		_music->get_object()->set_position(engine.audio_latency()
+		                                   / _music->get_object()->get_length_in_sec());
 	}
 
 	Meta_system::~Meta_system()
 	{
+		_music->stop_fade(2.f);
 		_renderer->device().wait_idle();
 		_entities.clear();
 	}
 
 	void Meta_system::update(mirrage::util::Time dt)
 	{
+		if(_play_music) {
+			_play_music = false;
+			_music->play();
+		} else if(_first_frame) {
+			_play_music  = true;
+			_first_frame = false;
+		}
+
 		_entities.process_queued_actions();
 
 		_beat_system->update(dt);
diff --git a/src/meta_system.hpp b/src/meta_system.hpp
index e424a475f4a0edf58eb579332d87774f4abcf494..cbf157f05f66d140cd33446ed111329e5ab02f3e 100644
--- a/src/meta_system.hpp
+++ b/src/meta_system.hpp
@@ -1,9 +1,10 @@
 #pragma once
 
-#include <audio.hpp>
 #include <mirrage/ecs/ecs.hpp>
 #include <mirrage/gui/debug_ui.hpp>
 #include <mirrage/utils/units.hpp>
+
+#include <audio.hpp>
 #include <sinks/sdl_sink.hpp>
 
 namespace mirrage {
@@ -64,7 +65,6 @@ namespace phase_shifter {
 
 	  private:
 		mirrage::ecs::Entity_manager                          _entities;
-		eam::audio                                            _audio;
 		std::unique_ptr<mirrage::renderer::Deferred_renderer> _renderer;
 		std::unique_ptr<mirrage::renderer::Loading_system>    _model_loading;
 		std::unique_ptr<audio::Sound_manager>                 _sound_manager;
@@ -81,6 +81,9 @@ namespace phase_shifter {
 		std::unique_ptr<gameplay::Dash_system>              _dash_system;
 		std::unique_ptr<gameplay::Stationary_attack_system> _stationary_attack_system;
 		std::unique_ptr<ui::Effect_system>                  _effect_system;
+		std::shared_ptr<eam::context>                       _music;
+		bool                                                _first_frame = true;
+		bool                                                _play_music  = false;
 
 		mirrage::util::Console_command_container _commands;
 	};
diff --git a/src/sync_screen.cpp b/src/sync_screen.cpp
index 0470a2d9c6afdc98f6955dea37bc04cd1b56fa3e..799e6dde30e97e1f0524de455c70502e6e57c8b6 100644
--- a/src/sync_screen.cpp
+++ b/src/sync_screen.cpp
@@ -1,7 +1,9 @@
 #include "sync_screen.hpp"
 
+#include "audio/audio_asset.hpp"
 #include "game_engine.hpp"
 #include "intro_screen.hpp"
+#include "ui/util.hpp"
 
 #include <mirrage/gui/gui.hpp>
 #include <mirrage/input/input_manager.hpp>
@@ -12,13 +14,14 @@
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 
+#include <algorithm>
 #include <chrono>
 #include <cstdlib>
 #include <iomanip>
 #include <sstream>
 #include <thread>
 
-
+#include <context.hpp>
 
 namespace phase_shifter {
 	using namespace mirrage;
@@ -33,6 +36,12 @@ namespace phase_shifter {
 	  , _mailbox(engine.bus())
 	  , _renderer(dynamic_cast<Game_engine&>(engine).renderer_factory().create_renderer(
 	            mirrage::util::nothing, {renderer::render_pass_id_of<renderer::Clear_pass_factory>()}))
+	  , _gui(&_engine.gui())
+	  , _audio(&static_cast<Game_engine&>(_engine).audio())
+	  , _start_audio_calibration_text("Press any button to start . . .")
+	  , _start_video_calibration_text("Press any button to start . . .")
+	  , _countdown(3)
+	  , _signal("o")
 	{
 		_mailbox.subscribe_to([&](Once_action& e) {
 			switch(e.id) {
@@ -40,12 +49,19 @@ namespace phase_shifter {
 					// TODO: show pause menu, instead
 					_engine.screens().leave();
 					break;
+				case "the_button"_strid: _on_button_press(); break;
 			}
 		});
 	}
 	Sync_screen::~Sync_screen() noexcept = default;
 
-	void Sync_screen::_on_enter(mirrage::util::maybe<Screen&>) { _mailbox.enable(); }
+	void Sync_screen::_on_enter(mirrage::util::maybe<Screen&>)
+	{
+		_mailbox.enable();
+		auto beat_sound = _engine.assets().load<std::shared_ptr<eam::opus>>("audio:beat"_aid);
+		_beat           = _audio->generate_context_ptr(beat_sound.get_blocking());
+		_beat->get_object()->set_loops(5);
+	}
 
 	void Sync_screen::_on_leave(mirrage::util::maybe<Screen&>) { _mailbox.disable(); }
 
@@ -54,21 +70,186 @@ namespace phase_shifter {
 		std::this_thread::sleep_for(std::chrono::milliseconds(8));
 		_mailbox.update_subscriptions();
 		_renderer->update(dt);
+		switch(_current_mode) {
+			case mode::start_audio_calibration: _start_audio_calibration_text.update(dt); break;
+			case mode::countdown_audio_calibration:
+				_countdown.update(dt);
+				if(_countdown.finished()) {
+					_countdown.reset(3);
+					_current_mode = mode::audio_calibration;
+				}
+				break;
+			case mode::audio_calibration:
+				if(_play_sample) {
+					_beat->play();
+					_play_sample = false;
+					_start       = std::chrono::high_resolution_clock::now();
+				}
+				if(_audio_latencies.size() == 5) {
+					std::this_thread::sleep_for(std::chrono::seconds(1));
+					_audio_latency =
+					        std::accumulate(_audio_latencies.begin() + 1, _audio_latencies.end() - 1, 0.f)
+					        / 3.f;
+					_current_mode = mode::start_video_calibration;
+				}
+				break;
+			case mode::start_video_calibration: _start_video_calibration_text.update(dt); break;
+			case mode::countdown_video_calibration:
+				_countdown.update(dt);
+				if(_countdown.finished()) {
+					_countdown.reset(3);
+					_current_mode = mode::video_calibration;
+				}
+				break;
+			case mode::video_calibration:
+				if(_play_sample) {
+					_play_sample = false;
+					_start       = std::chrono::high_resolution_clock::now();
+				}
+				_signal.update(dt);
+				if(_video_latencies.size() == 5) {
+					_video_latency =
+					        std::accumulate(_video_latencies.begin() + 1, _video_latencies.end() - 1, 0.f)
+					        / 3.f;
+					static_cast<Game_engine&>(_engine).audio_latency(_audio_latency);
+					static_cast<Game_engine&>(_engine).video_latency(_video_latency);
+					LOG(plog::debug) << "audio latency: " << _audio_latency;
+					LOG(plog::debug) << "video latency: " << _video_latency;
+					_engine.screens().enter<Intro_screen>();
+				}
+				break;
+			default: break;
+		}
+	}
+
+	auto Sync_screen::_on_button_press() -> void
+	{
+		switch(_current_mode) {
+			case mode::start_audio_calibration:
+				_play_sample  = true;
+				_current_mode = mode::countdown_audio_calibration;
+				break;
+			case mode::audio_calibration:
+				_end = std::chrono::high_resolution_clock::now();
+				_audio_latencies.emplace_back(
+				        std::chrono::duration_cast<std::chrono::milliseconds>(_end - _start).count()
+				        / 1000.f);
+				_start = std::chrono::high_resolution_clock::now();
+				break;
+			case mode::start_video_calibration:
+				_play_sample  = true;
+				_current_mode = mode::countdown_video_calibration;
+				break;
+			case mode::video_calibration:
+				_end = std::chrono::high_resolution_clock::now();
+				_video_latencies.emplace_back(
+				        std::chrono::duration_cast<std::chrono::milliseconds>(_end - _start).count()
+				        / 1000.f);
+				_start = std::chrono::high_resolution_clock::now();
+				break;
+			default: break;
+		}
 	}
 
 	void Sync_screen::_draw()
 	{
 		_renderer->draw(); //< clear screen
 
-		ImGui::PositionNextWindow(
-		        glm::vec2(500, 500), ImGui::WindowPosition_X::center, ImGui::WindowPosition_Y::center);
-		if(ImGui::Begin("Sync")) {
-			ImGui::TextUnformatted("TODO");
-			if(ImGui::Button("OK")) {
-				_engine.screens().enter<Intro_screen>();
-			}
+		auto viewport = _gui->viewport();
+		auto font     = _gui->find_font("default"_strid);
+
+		ui::push_font(font);
+
+		ImGui::PositionNextWindow(glm::vec2(viewport.z, viewport.w),
+		                          ImGui::WindowPosition_X::center,
+		                          ImGui::WindowPosition_Y::center);
+		if(ImGui::Begin("Sync",
+		                nullptr,
+		                ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize
+		                        | ImGuiWindowFlags_NoBackground)) {}
+		switch(_current_mode) {
+			case mode::start_audio_calibration: _draw_start_sync_audio_ui(); break;
+			case mode::countdown_audio_calibration: _draw_countdown_sync_audio_ui(); break;
+			case mode::start_video_calibration: _draw_start_sync_video_ui(); break;
+			case mode::countdown_video_calibration: _draw_countdown_sync_video_ui(); break;
+			case mode::video_calibration: _draw_sync_video_ui(); break;
+			default: break;
 		}
 		ImGui::End();
+
+		ui::pop_font(font);
 	}
 
+	auto Sync_screen::_draw_start_sync_audio_ui() -> void
+	{
+		auto viewport     = _gui->viewport();
+		auto heading_font = _gui->find_font("heading"_strid);
+		auto sub_heading  = _gui->find_font("sub_heading"_strid);
+
+		ui::push_font(heading_font);
+		ui::text_centered("Calibrate your audio output",
+		                  glm::vec2{viewport.z, viewport.w},
+		                  glm::vec2{0.f, viewport.w / 2.f - 70.f},
+		                  ui::center::horizontal);
+		ui::pop_font(heading_font);
+		ui::text_centered("Press any button when you hear the sound",
+		                  glm::vec2{viewport.z, viewport.w},
+		                  glm::vec2{0.f, viewport.w / 2.f},
+		                  ui::center::horizontal);
+		ui::push_font(sub_heading);
+		_start_audio_calibration_text.draw_centered(glm::vec2{viewport.z, viewport.w},
+		                                            glm::vec2{0.f, viewport.w / 2.f + 220.f},
+		                                            ui::center::horizontal);
+		ui::pop_font(sub_heading);
+	}
+
+	auto Sync_screen::_draw_countdown_sync_audio_ui() -> void
+	{
+		auto viewport = _gui->viewport();
+		auto huge     = _gui->find_font("huge"_strid);
+		ui::push_font(huge);
+		_countdown.draw_centered(glm::vec2{viewport.z, viewport.w});
+		ui::pop_font(huge);
+	}
+
+	auto Sync_screen::_draw_sync_audio_ui() -> void {}
+
+	auto Sync_screen::_draw_start_sync_video_ui() -> void
+	{
+		auto viewport     = _gui->viewport();
+		auto heading_font = _gui->find_font("heading"_strid);
+		auto sub_heading  = _gui->find_font("sub_heading"_strid);
+
+		ui::push_font(heading_font);
+		ui::text_centered("Calibrate your video output",
+		                  glm::vec2{viewport.z, viewport.w},
+		                  glm::vec2{0.f, viewport.w / 2.f - 70.f},
+		                  ui::center::horizontal);
+		ui::pop_font(heading_font);
+		ui::text_centered("Press any button when you see the dot",
+		                  glm::vec2{viewport.z, viewport.w},
+		                  glm::vec2{0.f, viewport.w / 2.f},
+		                  ui::center::horizontal);
+		ui::push_font(sub_heading);
+		_start_video_calibration_text.draw_centered(glm::vec2{viewport.z, viewport.w},
+		                                            glm::vec2{0.f, viewport.w / 2.f + 220.f},
+		                                            ui::center::horizontal);
+		ui::pop_font(sub_heading);
+	}
+	auto Sync_screen::_draw_countdown_sync_video_ui() -> void
+	{
+		auto viewport = _gui->viewport();
+		auto huge     = _gui->find_font("huge"_strid);
+		ui::push_font(huge);
+		_countdown.draw_centered(glm::vec2{viewport.z, viewport.w});
+		ui::pop_font(huge);
+	}
+	auto Sync_screen::_draw_sync_video_ui() -> void
+	{
+		auto viewport = _gui->viewport();
+		auto huge     = _gui->find_font("huge"_strid);
+		ui::push_font(huge);
+		_signal.draw_centered(glm::vec2{viewport.z, viewport.w});
+		ui::pop_font(huge);
+	}
 } // namespace phase_shifter
diff --git a/src/sync_screen.hpp b/src/sync_screen.hpp
index c7bd4afc47ffcc090558225250c4e567e051e119..b6d744ee136d74f3729f6841ecdbc657dfe6c65c 100644
--- a/src/sync_screen.hpp
+++ b/src/sync_screen.hpp
@@ -1,11 +1,18 @@
 #pragma once
 
+#include "ui/countdown.hpp"
+#include "ui/fading_text.hpp"
+
 #include <mirrage/engine.hpp>
 #include <mirrage/gui/gui.hpp>
 #include <mirrage/renderer/deferred_renderer.hpp>
 #include <mirrage/utils/console_command.hpp>
 #include <mirrage/utils/maybe.hpp>
 
+#include <audio.hpp>
+
+#include <chrono>
+
 
 namespace phase_shifter {
 
@@ -17,6 +24,15 @@ namespace phase_shifter {
 		auto name() const -> std::string override { return "Gameover"; }
 
 	  protected:
+		enum class mode {
+			start_audio_calibration,
+			countdown_audio_calibration,
+			audio_calibration,
+			start_video_calibration,
+			countdown_video_calibration,
+			video_calibration
+		};
+
 		void _update(mirrage::util::Time delta_time) override;
 		void _draw() override;
 
@@ -28,9 +44,32 @@ namespace phase_shifter {
 			return mirrage::Prev_screen_policy::discard;
 		}
 
+		auto _on_button_press() -> void;
+		auto _draw_start_sync_audio_ui() -> void;
+		auto _draw_countdown_sync_audio_ui() -> void;
+		auto _draw_sync_audio_ui() -> void;
+		auto _draw_start_sync_video_ui() -> void;
+		auto _draw_countdown_sync_video_ui() -> void;
+		auto _draw_sync_video_ui() -> void;
+
 	  protected:
 		mirrage::util::Mailbox_collection                     _mailbox;
 		std::unique_ptr<mirrage::renderer::Deferred_renderer> _renderer;
+		mirrage::gui::Gui*                                    _gui;
+		eam::audio*                                           _audio;
+		mode                                                  _current_mode = mode::start_audio_calibration;
+		std::chrono::time_point<std::chrono::high_resolution_clock> _start;
+		std::chrono::time_point<std::chrono::high_resolution_clock> _end;
+		bool                                                        _play_sample = true;
+		std::vector<float>                                          _audio_latencies;
+		float                                                       _audio_latency = 0.f;
+		std::shared_ptr<eam::context>                               _beat;
+		std::vector<float>                                          _video_latencies;
+		float                                                       _video_latency = 0.f;
+		ui::Fading_text                                             _start_audio_calibration_text;
+		ui::Fading_text                                             _start_video_calibration_text;
+		ui::Countdown                                               _countdown;
+		ui::Fading_text                                             _signal;
 	};
 
 } // namespace phase_shifter
diff --git a/src/ui/countdown.hpp b/src/ui/countdown.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..b40c8ff3160fced3f36cc85f926e624ac950a889
--- /dev/null
+++ b/src/ui/countdown.hpp
@@ -0,0 +1,50 @@
+#pragma once
+
+#include "util.hpp"
+
+namespace phase_shifter::ui {
+	class Countdown {
+	  public:
+		Countdown(int initial_value) : _value(initial_value) {}
+
+		auto update(mirrage::util::Time dt)
+		{
+			if(_value == 0) {
+				return;
+			}
+
+			_elapsed_time += dt.value();
+			if(_elapsed_time >= 1.f) {
+				_elapsed_time = 0.f;
+				--_value;
+			}
+		}
+
+		auto draw(const glm::vec2& position)
+		{
+			if(_value == 0) {
+				return;
+			}
+			text(std::to_string(_value), position);
+		}
+		auto draw_centered(const glm::vec2& window_size,
+		                   const glm::vec2& position = glm::vec2{0.f},
+		                   center           center   = center::all)
+		{
+			if(_value == 0) {
+				return;
+			}
+			text_centered(std::to_string(_value), window_size, position, center);
+		}
+		auto finished() const noexcept { return _value == 0; }
+		auto reset(int initial_value)
+		{
+			_value        = initial_value;
+			_elapsed_time = 0.f;
+		}
+
+	  private:
+		int   _value;
+		float _elapsed_time = 0.f;
+	};
+} // namespace phase_shifter::ui
diff --git a/src/ui/fading_text.hpp b/src/ui/fading_text.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..61462898170dc813737d0a79c4a9777470003037
--- /dev/null
+++ b/src/ui/fading_text.hpp
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "util.hpp"
+
+namespace phase_shifter::ui {
+	class Fading_text {
+	  public:
+		Fading_text(const std::string& text, float duration = 0.5f) : _text(text), _duration(duration) {}
+
+		auto update(mirrage::util::Time dt)
+		{
+			_elapsed_time += dt.value();
+			if(_elapsed_time >= _duration) {
+				_draw         = !_draw;
+				_elapsed_time = 0.f;
+			}
+		}
+		auto draw(const glm::vec2& position)
+		{
+			if(_draw) {
+				text(_text, position);
+			}
+		}
+		auto draw_centered(const glm::vec2& window_size,
+		                   const glm::vec2& position = glm::vec2{0.f},
+		                   center           center   = center::all)
+		{
+			if(_draw) {
+				text_centered(_text, window_size, position, center);
+			}
+		}
+
+	  private:
+		std::string _text;
+		float       _duration;
+		float       _elapsed_time = 0.f;
+		bool        _draw         = true;
+	};
+} // namespace phase_shifter::ui
diff --git a/src/ui/util.hpp b/src/ui/util.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..7c257658ca524fd95c64091c3e845d1454ccb3f3
--- /dev/null
+++ b/src/ui/util.hpp
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <string>
+
+#include <mirrage/gui/gui.hpp>
+
+namespace phase_shifter::ui {
+	inline auto text(const std::string& text, const glm::vec2& position)
+	{
+		auto cursor = ImGui::GetCursorPos();
+		ImGui::SetCursorPos(ImVec2(position.x, position.y));
+		ImGui::TextUnformatted(text.c_str());
+		ImGui::SetCursorPos(cursor);
+	}
+
+	enum class center { horizontal, vertical, all };
+
+	inline auto text_centered(const std::string& text,
+	                          const glm::vec2&   window_size,
+	                          const glm::vec2&   position = glm::vec2{0.f},
+	                          center             center   = center::all)
+	{
+		auto text_size = ImGui::CalcTextSize(text.c_str());
+		auto centered_position =
+		        0.5f * glm::vec2{window_size.x, window_size.y} - 0.5f * glm::vec2{text_size.x, text_size.y};
+		if(center == center::vertical) {
+			centered_position.x = position.x;
+		} else if(center == center::horizontal) {
+			centered_position.y = position.y;
+		}
+		ui::text(text, centered_position);
+	}
+
+	inline auto push_font(mirrage::util::maybe<ImFont*> font)
+	{
+		if(font.is_some()) {
+			ImGui::PushFont(font.get_or_throw());
+		}
+	}
+
+	inline auto pop_font(mirrage::util::maybe<ImFont*> font)
+	{
+		if(font.is_some()) {
+			ImGui::PopFont();
+		}
+	}
+} // namespace phase_shifter::ui