Now, with the latest version of the Rainbow app for iOS devices, other developers can upload files to any cloud through the Rainbow app.
If you are interested I can post code and instructions.
If you would like to see this in action, you can download the iPinPoint app and tap on the Share button.Links
Rainbow: https://itunes.apple.com/us/app/rainbow-sync-files-folders/id531874282?mt=8
iPinPoint: https://itunes.apple.com/us/app/ipinpoint-angle-length-measurement/id404645257?mt=8