As a former math teacher, I'm familiar with needing to communicate with a large group of students after a school day. I've needed to remind them to bring in signed gradesheets, or let them know about a schedule change. I've used email which works for the students with email addresses and whose parents allow them to use email on a school night. However, for the kids who don't have a computer at home or can't check their email, I had trouble getting ahold of them and didn't have the time to call each individually.

Inphonite's ShoutOut (Shoutout.inphonite.com) service is a great solution to that dilemma.

It's a free text to voice call program. At a math teachers' conference last year, the instructors recommended a few websites that could do text-to-voice. However, they either cost money per call or the text-to-voice was so unintelligible that the message was missed. I've used ShoutOut and it's better at converting text to speech. I tested with "I like to read. I read a book." and it differentiated between the two "read" pronunciations correctly.

Teachers can use this to remind students to complete and bring in homework, let them know about a special class activity, remind them if class is in a different building, or other such uses. The system is limited to 25 calls per email address per day and one call per phone number per day. If you have multiple email addresses, you can send 25 messages from each one and reach all of your students.

I would recommend Inphonite ShoutOut to any teacher for standard classroom reminders.