Candy Crush Saga is a great game to enjoy as a study break.
You match the colored candies (red, orange, yellow, green, blue, and purple) to remove them from the board. Try to match more than 3 candies of the same color to get more points.
You progress along a board game/world of different boards, some of which have challenges like jelly that you have to pop or acorns and cherries that you have to manipulate off of the board.
The best part of Candy Crush Saga is that once you lose 5 lives (i.e. the board defeats you 5 times), you have to wait before you can play again.
Perfect study break!