Eric Benvin found Socrative:

• Reduces teacher workload“I use it a supplement to the work I give my students. I supply them notes and a worksheet. The socrative is an additional tool.”
• Improves teaching efficiency“It provides an efficient way for students to review material that gives explanations.”
• Builds student knowledge“It builds on knowledge that has started in class.”
• Improves attainment“Yes, it allows students to practice as often as they would like.”