When you access a file on the mobile app – unless it’s a video or music file that streams straight from SecureBackup – it is cached locally on your device. This means that when you next want to access it you don’t have to wait for it to download. Once your cache is full, older files that you haven’t used recently will “roll over” and be removed from the cache. If you need more space on your device and want to reduce the cache size, go to Settings and change the Cache Size option – the smaller it is, the less space it will use on your device, but the more likely it is that SecureBackup will have to download files when you view them.