Kona's Crate is a fun little physics puzzle game that doesn't bother too much with a premise -- it just gets straight to the gameplay, and that's a good thing. You control what's basically a floating platform, and by tapping on either side of the screen, you can make rockets push on one side or the other, carrying the crate across a series of levels. It's a weird idea (why is a jet-powered platform carrying crates to a voodoo priest?), but the gameplay is easy to pick up, and since the stages ramp up in complexity and difficulty, the premise stays intriguing as you progress along.
Each stage can nab you up to three stars, so there's a little bit of replayability in going back and trying to do them better and faster. There's over 60 levels now, with more coming, and one nice thing about the game is that it provides both OpenFeint and Game Center integration, with a really easy screen that allows you to decide where your scores go.
Kona's Crate is a fun physics puzzler with plenty of content, and definitely worth the US 99 cents it's selling for in the App Store (either iPhone or iPad, but it's the same price for each one). There's a lite version to check out if you're not sure of the gameplay yet, but I'd even recommend this one sight unseen if you enjoy a good physics game.