There's no shortage of quick and fun puzzle games on Android, and Shift It still stands out as a great one. When you start up Shift It and play the first level, you'll instantly draw comparisons to the paradigm of a Rubik's cube. The basic idea of the game is to take the nine section grid of different colored blocks, and move it around so that the blocks of the same color are all connected. You are faced with a 2D view, but the blocks are effectively 3D -- moving blocks off of one edge, you will see them reappear on the other side.
The game starts of simply, but picks up eventually to introduce different types of blocks to maneuver around. You get a star rating per level based on the number of moves it takes you to complete, which is pretty common in most games of this type by now. You can use hints to help you through tough levels, and an undo button if you'd prefer not to completely start over when you mess up.
There are four difficulty levels, each with 60 levels in it. You unlock the next difficulty by reaching a certain number of stars, but if you're impatient you can use an in-app purchase to unlock it sooner at the rate of $0.99 per unlock. You can also jump right into the "Lightning" game mode with a $0.99 unlock. Shift It is otherwise free, and only displays ads at the bottom of the game between levels.
It's hard not to recommend a smooth, fun and free puzzle game. Even if you're anxious and want to unlock a few things with in-app purchases, the game is still worth it. If you're into mind-bending games that are easy to pick up and play at your own pace, check out Shift It from the Play Store link at the top of this post.