Google Docs
Google Docs provides a free way to collect responses called Forms.
While there is a free Poll Everywhere plan for K-12 classrooms, the $50 per year plan gives teachers the ability to see individual student responses and to approve text-based responses before they appear for the whole class to see
QuestionPress
QuestionPress (formerly QuickieQ) is a 100% web-based audience and classroom response/assessment tool.
eClicker Host
An option for iPad, iPhone, or iPod touch using teachers is the eClicker Host app. Priced at $9.99, it's a very affordable solution because no subscription is required.
The Nintendo DSi and Sony PSP both have browsers that can be used. If they can get online at school.
The best feature is being able to email the results to yourself. It makes it easy to record grades.
Hi Everyone,I warmly recommend to check Socrative.com it includes real time formative assessment, exit tickets and games.