Socrative… Thanks to MathyCathy for this one. You create a quiz. Students access the quiz online via a web browser or an iPhone/iPad app. The quiz gives immediate feedback as they answer each question, then emails the teacher a nice color-coded spreadsheet with each student’s response.
Remind101… send text/email announcements to students/parents without ever sharing your phone number or email.
TeacherKit… iPad app with many nice teacher features. The one I like is seating charts that you can TAP on to edit attendance. You can then see the information by date or by student.