Plants vs. Zombies 2 is now out on iOS, playable on iPhone and iPad.
Unlike its predecessor, the game itself is free-to-play and offers in-app purchases, i.e. microtransactions, in the form of new plants and upgrades.
Plants vs. Zombies 2 was announced on August 2012. It was slated for release on July 18, 2013, but was then delayed to August 15.