Upvote for Joe's comment, and my compliments on a really great list : )
I would add to it:
--Lords of Waterdeep: Remains one of the best worker-placement games going, and the app is excellent. Beautifully designed, easy to use UI, and great tutorial. The async multiplayer works perfectly, and solo games are challenging.
--Ticket to Ride: Again, great UI and beautifully designed. They keep adding new maps with unique rules to keep the game fresh, and online games work well, with solo games being very challenging at times.
Terra Mystica would not have made my list because I found the tutorial to be not very helpful to someone who'd never played the board game (aka: Me). I think if you already know how to play, it's easier to figure out the app, but I regret the purchase, honestly.