I use very few apps and the Pebble is pretty ancient and outdated. I mainly use it to see who is calling and texting me. I can respond with canned messages and send basic texts (and it doesn't look like a smartwatch). There are a few other outdated Pebble apps. Looks like all pebble apps can work.
Haven't tried anything else, sorry
Look up Gadgetbridge. It lists all the smartwatches that work with it.