Relaxing games for the iPad

Anyone having some recommendations for iOS games, preferably iPad-optimized/universal, that are really relaxing?

I'm talking about the type of games, usually casual games, that won't stress you with hard time limits, brain flexing puzzles or deep, immersive story-lines. The ones that allow you to jump in for either 5 minutes or 5 hours while you're brain is mostly on suspense. :)

Think Bejeweled, Zen Bound, Drop7, XenoCube, Flower Board and even Mahjong.