This app was mentioned in 4 comments, with an average of 1.50 upvotes
Harmony Smart Remote. It's not the worst thing ever, but it'd be so easy to make a decent icon for a smart wifi universal remote.
Logitech Harmony app - rather than buy additional remotes, you can re purpose any android device with Wifi as a remote control for your media equipment.
https://play.google.com/store/apps/details?id=com.logitech.harmonyhub&hl=en
edit: of course, you need to own/buy the logitech hub too!
https://www.logitech.com/en-us/harmony-universal-remotes
The harmony hub can interact by bluetooth, IR, RF and some web API with some devices, and you can interact with the hub with the android application:
https://play.google.com/store/apps/details?id=com.logitech.harmonyhub&hl=en_US
But, imho the UI is not really pleasant.