Ive been using this app since January 2013 and almost 20% of the time, I have to copy my friends notes due to the app deleting all my notes (for the current message). It has happened to my other iPhone friends as well.
Its a double-edge sword, because want to use it and like it, but when it crashes at the end of a message, you lose a little joy. I highly recommend having someone else to copy from as a backup. If youre luck enough to get all notes - Email yourself a copy ASAP!
Like others have said, there are no backups. If you lose your device, you lose everything. It would be nice if you could backup "somewhere in the cloud." Evernote, GoogleDocs, or even a Saddleback Church login for syncing would be VERY appreciative. Maybe the next version will resolve this issue.
Another thing Id like to have is the ability to delete messages when I want, but no option for that yet.