Blackbar (text based communication used as the medium for the game, but with key words blocked out that you need to guess). has a prequel I have not played called greyout.
Pry (VIdeo, but still built into the fiction that you are using a phone app for phone things as you play
BlackBox. (The ultimate in making a NATIVE mobile game. It literally could not work if it was running on anything else. It's a puzzle game, so I don't want to say too much, but it utilizes every sensor and software API the phone has to create truly difficult puzzles. Many times I have been surprised to learn my phone even could do what the puzzle requires. And, as something cool, the developer, recently re-tooled the whole game to be playable with assistive tech — so you can play even if you are blind, or otherwise need accommodation — Very cool, but sadly rare in video games.).
Florence (not really related, its just a good mobile game people should be playing)
Edit: decided to form my words into sentences.