"Progress to 100" doesn't sound like the most exciting name for a game, but this clean, two-toned series of iOS puzzles is a real crowd pleaser. It might offer you just a single word, and using the functions of your device—tilt it in a certain pattern, lift it up, touch it as suggested—you satisfy the puzzle.
Some of these are simple, like a prompt to close a gap, and others swell mischievously with a-ha moments—you might, for example, flap the iPad helplessly in response to a prompt about birds, only to realize with a pleasant dawn of intuition that you simply need to hold the screen above your head and crane your neck.
It's low-key; solving one hundred of these feels like an attainable goal. I mean, probably. Try it. After gaining popularity and recognition on the festival circuit, it's officially available today.
In general I'm very fond of social tablet and phone games, ones that you can hand around to friends or place on the table for open collaboration. It's wonderful to get well and truly stuck on something that is much more intuitive to someone else than it is to you, and Progress to 100 is full of opportunities for that.
It's a good excuse to update to the latest version of iOS, which Progress to 100 requires. The game, for both iPhone and iPad, is $2.99 on the App Store.