I am about to finish improving the software soon. We ask different people to test that I know what to work on.
Below is a list of links that I used to create the software:

1. https://www.alanzucconi.com/2015/10/07/how-to-integrate-arduino-with-unity/
2. https://stackoverflow.com/questions/25781692/an-object-reference-is-required-for-the-non-static-field-method-or-property-co
3. https://docs.unity3d.com/ScriptReference/Input.GetKeyDown.html
4. https://developer.vuforia.com/forum/ground-plane/using-ground-plane-lights-and-shadows
5. https://www.arduino.cc/en/Serial/Write
6. https://www.arduino.cc/en/tutorial/button
7. https://forum.arduino.cc/index.php?topic=449678.0
8. https://www.arduino.cc/en/Tutorial/StateChangeDetection
9. https://www.arduino.cc/reference/en/language/functions/time/delay/
10. https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/conditional-operator
11. https://stackoverflow.com/questions/1019793/how-can-i-convert-string-to-int
12. https://docs.microsoft.com/pl-pl/dotnet/csharp/programming-guide/types/how-to-convert-a-string-to-a-number
13. http://forum.arduinopolska.pl/watek-biblioteka-timers-koniec-z-uci%C4%85%C5%BCliwym-delay
14. https://starter-kit.nettigo.pl/2016/04/biblioteka-timers-16-4-0/
15. https://www.arduino.cc/reference/en/language/functions/analog-io/analogread/
16. https://forum.arduino.cc/index.php?topic=45387.0
17. https://www.dotnetperls.com/list-add
18. https://www.alanzucconi.com/2017/02/15/nested-coroutines-in-unity/
19. https://docs.microsoft.com/pl-pl/dotnet/csharp/language-reference/keywords/switch
20. https://answers.unity.com/questions/728588/reset-the-timetime-back-to-00.html
21. https://www.c-sharpcorner.com/UploadFile/mahesh/delete-all-items-in-a-C-Sharp-list/
22. https://docs.unity3d.com/ScriptReference/SceneManagement.SceneManager.LoadScene.html
23. https://docs.unity3d.com/ScriptReference/Time-deltaTime.html
24. https://docs.unity3d.com/ScriptReference/Time.html
25. https://answers.unity.com/questions/910789/play-sound-on-object-in-another-scene-with-button.html
26. https://forum.unity.com/threads/dont-destroy-on-load.511621/
27. https://answers.unity.com/questions/267213/there-are-2-audio-listeners-in-the-scene-please-en.html
28. https://stackoverflow.com/questions/29924725/change-color-of-text-during-runtime-unity
29. https://docs.unity3d.com/ScriptReference/WaitForSecondsRealtime.html
30. https://docs.unity3d.com/Manual/StyledText.html
31. https://answers.unity.com/questions/225213/c-countdown-timer.html
32. https://answers.unity.com/questions/329768/preventing-my-game-object-from-multiplying-due-to.html
33. https://docs.unity3d.com/ScriptReference/UI.Text.html
34. https://answers.unity.com/questions/864840/how-to-access-textscript-component-in-unity.html
35. https://www.youtube.com/watch?v=7s5bEWZycHQ

@izabelatyprowicz