Outside of QR scans, I believe I've caught everything I can, for the time being. Plus Klink. Well, excluding Pikachu, but Pichu will evolve, so I'm fine with that. Never ran into Pikachu or Munchlax. Or, any of the evolved forms via SOS battles. I'll probably wait until tomorrow, and try to catch Chikorita, and then go to the next island. Out of curiosity, though, is it easy to hop back and forth between the islands, or does the story lock you in place for a while?