Mine so far is wingspan, my dads been bugging me to download Root.
For me it would be Root all the way - especially with the expansions. It’s a brilliant adaptation! There’s a group of us who always have at least one game on the go it’s turned into a bit of an addiction…
Honourable mentions for Yellow & Yangtze and Concordia as well. Also solid apps for great games
Star Realms is pretty good for a quick few rounds during downtime.
Or the fantasy themed version Hero Realms! I slightly prefer this one, but both are great and you can try them for free.
The Star Realms app is far more well-supported though, with all major expansions and all but the last 2 mini expansions available, while the Hero Realms app is just the base set with no apparent plans to support it further.