Try the free version of the app first with one class.
https://play.google.com/store/apps/details?id=com.apps.ips.randomstudent2trial

Main Features
• select a student at random
• device speaks name aloud
• name quiz feature to learn student names quickly
• track correct and incorrect responses
• student groups

Students enjoy the 'speak aloud' feature in my classroom. Participation is more equitable and students enjoy participating in activities more when using the app.

Google Doc User Guide
http://docs.google.com/document/d/1PVSXNaSZapenlc0cV42JE2UUAKv_rshRKRoXs32cWuI/