Sprite Rips for Love Nikki?

[Sosfiro]

Yeah, you can open the apk with winrar, and if you have luck, you will be able to extract the image files. But not many games have all the files there. It's the case if is a game with many updates. I recommend you install the Bluestacks (Android emulator), install the apk, and download all the files (if the game has this option). Then, you "root" the emulator and access to the hidden files downloaded by the game.
Maybe it can be hard the first time, but if you try you can do it.
Ask me if you have any question.