@TerrorBite Seedship, Beyond the Chiron Gate, Hoplite and Threes! are all staples on mine.
Threes is a block-matching puzzle game about building ever larger numbers.
Hoplite is older so might be a little jank on your phone, but it's a simple but fun roguelike.
Beyond the Chiron Gate is a text RPG about exploring past an interstellar wormhole.
Seedship is a simple text RPG about finding the leftovers of Earth a new planet.