[Zubersoft]

That is really strange. Unfortunately, you'd need to talk with Amazon support to figure out why their app store is not letting you update the app. If you want to install an older companion version, you can find them archived here: http://zubersoft.com/mobilesheets/archive

It is really dangerous to restore a backup from a newer verison in an older version. At best, some features may not work correctly, and you will receive database errors when you try to access them. At worst, it could render the library unusable on that device. I definitely would recommend against doing that.

Mike