Walls (u-ndefined)

Tap to place a wall, repeat to rotate, repeat to remove. Alternatively, drag to create series of walls. There are two rules:

1. Every unobstructed ground tile must have a wall placed on it.
2. The numbers on a tower indicate the number of walls connected to it. 

Every level can be solved logically. Based on a logic puzzle invented by Naoki Inaba.

Also playable in Fancade