open the settings dialog, select manage backups and tap on + to create a backup. To upload it to Dropbox, just slide it to the left and select Share.
Instead of Dropbox you could also use iTunes Filesharing to transfer that file to your computer if you struggle with Dropbox.
Regarding the bad news: I have started working on version 3 again in July and work is currently progressing nicely. I don't want to make any preliminary announcements, but maybe I can continue working on Stage Traxx 🙂