When you upload your BeatBuddy library meta information to your device, the BBFF (https://bbff.rocks) servers are used purely as intermediaries to facilitate the transfer which is encrypted ussing SSL. None of your data is stored.
The upload process involves reading your BeatBuddy project within your browser, then only the song meta data (including things like name, tempo, sections, and drumset) are uploaded to your device. None of that information is stored on the BBFF servers.
If you have any questions about this process, please contact Andrew at bbff.rocks