Add more apps

I wanted to open a MR to add them directly, but I did not find an appropriate source file. All Android apps mentioned on the page are open source, so it would be nice to add the repo so it is evident.

Most importantly there is an open source iOS app called Amperfy, I have tested it and it works very smooth: https://apps.apple.com/us/app/amperfy-music/id1530145038