The default storage location for the QMemo files is in a hidden/secured folder on the internal storage. By default there is no recovery for these files.
If your G3 is already rooted, you might be able to use an "undelete" app to recover some/all of them.
You can "export" the files so that you have a backup of them, which you probably want to store off the phone.
I used to be a user of the QuickMemo app and files. However, I now use Google Keep which stores the files on Google Drive and allows for easy computer and phone updates of the files.