Open-source gym & body-weight tracker, now in the App Store (iPhone + Apple Watch) and as an Android APK. Plan routines, log workouts, see which muscles are trained, import from Strong/Hevy/FitNotes. Self-host it or use it on the phone alone.
The ultimate open-source Overleaf extension and alternative: a free, self-hosted, drop-in replacement for Overleaf Community Edition with nearly all Pro feature—SSO, AI Assistant, Git(Hub/Lab)/ Dropbox sync, track changes, sandboxed compilation, Zotero, Mendeley and more. Formerly @Ayaka-notes Overleaf Pro. Docs: https://ayakaleaf-pro.ayaka.space
Newsletters where you pay for the emails you send, not for dormant subscribers, at a fraction of the price of beehiiv and the like. Open source: self-host it, or use mailcheap.ai.