I don't know if there's something wrong with my installation, but the couple of latest versions have destroyed all the notes I've written if I go to the settings. At first I thought that it happened because I was always switching to portrait/landscape-mode, but I just noticed that the notes disappear if I just go to the settings and come back. It's of course impossible to use the app at the moment because of this, but like I said, the problem might be in my phone.
Mine disappeared just by updating to the latest version.