Lastly I was in a app, this app has 2 buttons, with a wave animation which became smaller as soon, as one clicked on it. Those were so small waves that were three-dimensional. The one button had green waves and the other red waves.
This has made the app 101% more professional and had a positive effect on the user.
I found after a long search on GitHub a project that brings exactly this effect.
@AndOrNot I told him to post it here. I was not aware he want to offer money for it. In this case, you are right, it would be better placed in JobForum.