50
Untracker - URL tracking parameter remover
(f-droid.org)
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
Matrix space | forum | IRC
I think being paid well makes it easier to commit time towards FOSS projects, so a lot of contributors are from similar backgrounds