Crescent Moon Games made the excellent Aralon for iOS in the past, and that was a full-fledged RPG, featuring a whole world to explore and lots of gear to collect and quests to complete. Now, the company's gone back to the fantasy well to deliver another hack-and-slash style RPG game, though this one is a little simpler (and a little more focused on just the dungeons). Pocket RPG is exactly what it sounds like: A colorful dungeon-crawler with three classes, a fun and slick style and some great dual-stick gameplay.
If there's an issue with this one, it's probably that things are a little too simple. Each level is its own contained world, which means you're leveling up what's basically a separate character in each. Gameplay itself is pretty mindless, too -- there are a few special encounters to break things up, but you're pretty much just using a few different abilities over and over against the enemy hordes.
Still, Pocket RPG is plenty of fun, and the game's being updated steadily with new features (not to mention that it comes with full Game Center integration, and it looks particularly great on the iPad). Right now, the title's on sale for just US $4.99, and if you enjoy plumbing through dungeons of all kinds (and come on, who doesn't?), it's an excellent experience.