It has been described as "a grid on which you play a game" and "a game which is played on a grid". If I were to describe GridGame in two words, those words would be "grid" and "game". If the question is "GridGame?", the answer is "Yes".
Here is the actual description:
This is a puzzle/logic/brain-teaser type game. There is a 5 by 3 grid of black and white cells. Touching a cell changes the color of all adjacent cells. The goal is to have all black cells.
The picture in the icon shows an example puzzle, which can be solved in two moves.
This is the free version, there's also a paid version that doesn't have ads.