I'm going to utilize Remind on a regular basis to communicate with parents and students. I learned the hard way this summer that hardly anyone, including parents, uses email any more. But they will look at and respond to text messages. For the "evidence of attainment" section, you can list the contact logs in Remind-- I'm sure you could print off all of that, if they wanted to have something to put in a file folder.

I'm not familiar with the Band app, but I'd guess you could use that in a similar fashion.