Seconded this. Very small too, at about 10 MiB! The Android port is probably the best but a Linux and Windows version also exist. Get it on F-Droid

There is also Gauguin, a similarly small app but with only 1 puzzle type, this one. There are more options though, including negative and non-consecutive numbers! The controls are a little worse if you ask me and so is the performance but not by a lot. I have spent huge amounts of time playing the game in both apps and I slightly prefer this one thanks to more variation.