Lights Out

Tap a light. It flips, and so do the lights above, below, left and right of it. Turn every light off. Fewer moves is better.

A trick that always works: chase the lights down

1. Start at the top row. For each light that is on, tap the light right below it. Do the same for each row, going down. Soon only the bottom row has lights.
2. Find that bottom row below. Tap the top-row lights it shows.
3. Chase the lights down again. The board goes dark.

It always works, but it is rarely the fewest moves. Spotting shortcuts is the game.