I've been keeping track of students who don't turn in assignments using Hedge's SWHHW form. But after having the students fill out the quarter-sheet piece of paper, I wasn't sure what to do with them. I'd been throwing them in a little crate with the idea of one day sorting them to go so I could talk with parents at conferences about why their son/daughter wasn't doing their homework. But you all know they were never going to get organized!
Until I saw an app called Three Ring. It's billed as an app to "Quickly and easily digitize student work and build the resource for authentic assessment in your classroom." I guess you could use it to take pictures or videos of student work/performances so you have evidence? Anyway, I'm using it to take pictures of each of the forms the kids fill out (using my iPad, but I think you could do it on your phone, too), and then I can assign it to an individual student (or class, if necessary). It's searchable by student or class.
Here's the link to Three Ring in the app store.