This app was mentioned in 18 comments, with an average of 1.61 upvotes
https://play.google.com/store/apps/details?id=com.scs.stellarforces.main.full . The graphics aren't that good, but it's been going for almost 10 years now. It was originally based on Laser Squad, which was made by the same person who went on to create X-Com.
I've got a few multiplayer strategy games, Stellar Forces probably being the most like Breach and Clear (in gameplay, not graphics, which bely it's complexity).
There aren't that many co-op games. There aren't that many asynchronous games. There's almost no asynchronous cooperative games.
If you can look past the graphics, Stellar Forces. It's completely free, no ads, so it's worth a try. Edit: has missions for 2, 3, and 4 people.
Stellar Forces has a few missions where players build defences and must raid other players defences. It's a TBS though, if you're looking for RTS.
I've created a few 2D multiplayer strategy games: Stellar Forces, Sorcerers and Nanowars. I'm currently working on a 2D Populous-style multiplayer game.
Definitely Stellar Forces. I've been playing it for years and not got bored yet.