How do I get .wav files made on the iPad into dropbox?
You can access the exported .wav files using the iTunes app on your Mac or PC when the iPad is plugged in through USB:



Select the Apps collection in the Sidebar, then scroll that window down to File Sharing. In the File Sharing list, you'll find iELECTRIBE, with all the exported .wav files. Drag the files from this list to your Desktop or folder. There seems to be no other way but to drag.

Until the developer creates the hooks that allow it to access Dropbox or Drive, this is the only way, other than SoundCloud.