Yes, you can use Dropbox sync between multiple different people and devices.
Road Trip does not currently support sharing between different iCloud accounts.
If you are currently using iCloud Sync, it’s always safe to switch between iCloud Sync and Dropbox Sync at any time.
If you’re not already a Dropbox user it’s a free service and you do not need to install the Dropbox app on your phone. Visit https://dropbox.com to create a new account (choose the Free 2GB plan), then sign in to your account in Road Trip.
It’s easy to set up syncing in Road Trip. Begin on the device that has your most recent Road Trip data:
Finally, repeat these steps on your other devices, using the same Dropbox account login.
Both copies of Road Trip will continue to sync automatically as you add and edit data.
For full instructions, follow the link below.