Have students use the IXL app on their ipads. The first time that anyone logs into the app, they must type the "@mankato", and then it will ask if they want to "save" the @mankato. If you click "yes" the students won't have to type that again.
You might want to go through and have one student fix this on all your classroom's ipads. If you have younger students, talk to a 4th or 5th grade teacher and have them send one of their techs to help you do your ipads. I just taught Boston in 4L to do his classes. He could come do lower grades...