Spellitaire arrived on the App Store last month as the first offering from Knucklehead Software, a studio consisting of two developers who've formerly worked for places like Valve and Blizzard. It's a simple game, which basically replaces the cards in solitaire for letters, which you then use to try to spell words and score as many points as possible within a five-minute time limit.
I like it for its simplicity, though -- some word games can get frantic or complicated, and this one basically sits back and lets you spell whatever you can think of within a very generous limit. Letterpress has gotten a lot of attention lately, and it's a very good word game, but it requires multiplayer and can be rather restrictive. It's nice to have a slower, solo game like Spellitaire around when you need it. You can see me spelling some words in the video below if you want to see the game in action.
Spellitaire is available from the App Store in a universal version for US$1.99 right now. The one big drawback is that it's not yet updated to work with the iPhone 5's bigger screen, but we can probably expect an update for that soon.