ownCloud needs a thumbnails API for files app so the clients such us the android one can show them when exploring files without having to download the entire files by the client in order to create thumbnails. Imagine a user with hundred of images inside a folder named as IMG06258.jpg who wants to download that nice pic of his trip and don't want having to remember crappy file names nor having to download file by file to find it. See https://github.com/owncloud/core/issues/86. Prerequisites: PHP