How do I change which folder this app is syncing to.
Instructions pertaining to that are on page 146 of the (Mac) user manual PDF, under Using Multiple Sync Folders.
In the Projects view on the iDevice:
Tap on Edit (at the top)
Tap on the gear wheel icon (at the bottom)
Tap on ‘Dropbox settings’ on the menu that pops up
Tap on ‘Other’ and locate the subfolder you want to use