In addition to the just-announced mainline games, Pokémon Let's Go, a new spin-off game has been announced - Pokémon Quest. It is available for Nintendo Switch right now, and will be available for mobile devices in June.
The game contains the original 151 Pokémon in a blocky form. They can be used in teams of 3 to battle and explore Tumblecube Island. Pokemon's characteristics can be changed using Power Stones. The game is "free to start" and has in-app purchases for certain things.