With the first release candidate, running on iOS 7.1, the app crashes once I authorize the second vault and tell it to sync with a separate Dropbox account. After authorization from Dropbox, it takes me back to the app, but then it just crashes. I've tried a clean reinstall of the app but it still is broken. I've sent the crash report each time it happened. Since we're so close to release, I assume multiple vault support is low on priority to fix.