I want to introduce you to Cardrooms.app : a free, guest-friendly, competitive platform for shithead (with plans to expand into other card games).
I based the main game on shithead because it is the best game that combines strategy, memorization, luck, and complexity. If you're not familiar with the rules there is a play through tutorial as well as documentation on how to play on the app,
It's still a really new project (1.5 weeks old at the time of writing) so I suggest trying it out with friends as its really hard to get an open room. It's great to play with your card game buddies especially when you're separated by distance or have no physical cards on you.
If you decide to make an account, there is a robust ELO system to help you track your performance against other players, with a global ranking system and some ingame cosmetics to reflect your progress through the ranks.
Any feedback is much appreciated. I'd also love to hear any ideas you have for promoting it - Discord servers, Facebook groups etc. Not really sure where the big online communities hang out (apart from here).
If you enjoy it, tell your friends!