It was designed to work with ST M24SR02 memories and as such we can currently not guarantee that it will work on larger memory devices.
To operate the app, move the phone close to the NFC antenna of the SweetPea device. if the NFC Tag is empty you will be asked if you want to initialize the Tag or not. If the Tag was already initialized you will be forwarded to the settings page where you now can alter network parameters for your SweetPea UnoNet+ board. Should you have started the app before coming into range of an antenna you will simply be asked to approach an available Nfc antenna.
Let us know how you get on with the app and what you think can be improved. If you'd like to fiddle with the source code your self it can be found at https://github.com/Sweet-Peas/NfcSettings and we gladly accept improvements and updates to it.