Teacher Kit Contacts
I've been using Teacher Kit (formerly Teacher Pal) for a couple of years now. I find it to be a useful tool, and have blogged about ways to use it as a classroom teacher here.
Being an Adjunct Professor means that I do need to keep track of what the group does. What's nice about using an app like this for college level is that it took no time at all to input the graduates into the app.
Once I created a 'class' for the group I was ready to 'add students'. All I had to do was click 'Add from Contacts', and voila! They were added. It imported their info from contacts, making it easy peasy to send a group email, too!