A free app for Android, by MONIA Studio.

LinkBox is a secure cloud storage and sharing service. You can upload files to the cloud, share them with your friends and family, and keep them private and protected. All files are encrypted and transmitted through secure channels, which makes it impossible for anyone to see what you’re doing or who you are sharing with.

LinkBox is the only service that supports sharing of private folders, which means that you can share folders with your contacts and see their updates in real time. The app also supports multi-terminal access to any file in your account, which means that you can access files on your mobile phone and view them in the app.