Feeel is an open-source app for doing simple at-home exercises. It holds the acclaimed full body scientific 7-minute workout regime and allows creating custom workouts as well. While the app currently contains a limited amount of exercises, the plan is to drastically expand the number of both exercises and workouts with the help of the community.
Contribute at https://gitlab.com/enjoyingfoss/feeel/wikis
Donate at https://liberapay.com/Feeel/ . Donations will let me work on the app regularly, rather than just in my free time.