Holdbit is cloud storage company based on Owncloud, an open source file sync and share app platform.
Desktop and mobile apps are made by OwnCloud community. It is open source, safe and easy to use apps.
Connecting your drive with those apps are very easy. You just need to enter Holdbit address in server field and your username in user field. And that's it. After that you will be synced with your drive. For server field use address of Holdbit web access https://holdbit.com/owncloud and username you will get after you order selected storage plan.