I’ve been using Liftosaur for more than an year now and it is perfect.
The app has many programs you can find on fitness forums and subreddits. But the developer is open to port more to the app if requested. You can build your own program with an easy interface or use a scripting language develop for the app to have total control
I selfhost Vikunja and have some colleagues and family on my instance. It’s a very complete task and project manager, specially useful to create teams and collaborate in tasks (either work or house related). In mobile I use Tasks.org, which syncs with Vikunja over the Caldav provided by Vikunja.
My goal is to lean typescript so I can program a sync add-on between Logseq and Vikunja