[ if korra's having a difficult time with her device, he may as well demonstrate on his own. so he takes it out of his pocket and shows korra his contacts list. ]

See this little tab at the bottom that says alarm?

[ tadashi clicks on it, and there's a toggle option that says on/off, and he has it on. ]

This is the one that'll tell you who's arrived, and whose codes got corrupted. It'll send you a text once a change has been made to your contacts list.

[ he says it slowly for korra to understand, looking at her every now and then for what her reaction might be. ]