Nurikabe is great logic game that is fun for all ages.

21000 grids ranging from small 5x5 up to large 10x10, including rectangular grids.

The goal is simple; fill the grid with rivers or islands following the game rules.
Rule 1. The river should be a single continuous flow.
Rule 2. Each island must contain one number and consist of that number of squares (counting the square with the number).
Rule 3. The river cannot consist of a 2x2 block of water (lake).

Smaller grids are great for younger players or if you just want a quick game. Larger grids will provide a challenge to even the best puzzle solvers.
Grids can be zoomed in and out using a spread and pinch motion to easily complete large grids even on smaller devices.