For Android, f-droid has a collection of open source games [0], I see they have a solitaire game as well [1].

F-droid is a repo of FOSS application for Android, quality vary widely but they are some nice gems.

[0] https://staging.f-droid.org/search?q=game&lang=en [1] https://f-droid.org/en/packages/de.tobiasbielefeld.solitaire...