Usually I do not play much on my Android phone. But when waiting for someone or something, to have a good puzzle is worth it.
Slitherlink, as you can look up in the Internet, is not an idea of this app author. It is a known puzzle, and if you look up in Google Play, you will notice a few implementations.
I can’t say that this one is the best, as I did not test any other. But it installed correctly, runs smoothly, and seems to have some good diversity of modes and difficulty levels. Therefore, I am quite happy with it, happy enough to consider buying the ad-free version, with extra levels. Truth be said, the free version includes a good mount of levels, and ads are not intrusive. So, kudos for that.
About the game, it is up to you to read about it and test it. It can be seen as some sort of minesweeper, with some reasoning mechanisms also used in sudoku.