If you like Magic The Gathering card playing game, avoid Forge (Desktop + Android) because it is open source (made in Java) and it has all the cards, gameplays, you can build your deck or choose from a huge list of ready-made ones and play against the AI and online up to 4 players in the same game I believe.
recently: https://news.ycombinator.com/item?id=38651346 and XMage is usually submitted alongside them when any M:TG makes the front page, including the quarterly(?) "M:TG is Turing complete" paper thread
https://github.com/Card-Forge/forge