We have just submitted the first update of DEVONthink To Go to version 1.0.1 to Apple for App Store review. The updated fixes a number of crashes and glitches including the crashes when navigating back from the Search screen as well as the non-functioning Cancel button on the Sync screen. The update will show up automatically on your device as soon as it has been approved by Apple.
A corresponding update for DEVONnote and all editions of DEVONthink that, e.g., fixes the not appearing ‘Sync’ group on some machines is scheduled for later this week, too.
Addendum: DEVONthink To Go 1.0.1 has been auto-released this morning by Apple and is available as an update through the App Store app.