Neko Atsume (ねこあつめ, literally means Collecting Cats) is an App for iOS and Android, popular in Japan and now has become popular other countries. In this game, you have your own virtual backyard and you put some cat food out on. And then some cats get gathering around. It is now only in Japanese, no English version, but you can understand it easily because it is just simple. Here is some how-to videos for Neko Atsume.