Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.
Clever - syncing between education applications for K-12 schools
TextMe - TextMe is a free calls and messaging application at both local and international levels.
Claroline - Claroline is a collaborative eLearning and eWorking platform.