I got the MP3 songs to work as a phone ringtone by creating a folder called "ringtones" in my files app, but I can't seem to get MP3 songs for text messaging ringtones. I tried press and holding the name of the song and waited for a pop up options menu, but it does not give the option to set as a ringtone. I have also tried going to the options menu to see if something would pop up, but I didn't see one.