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Free iPad app: http://itunes.apple.com/us/app/classdojo/id552602056?ls=1&mt=8&uo=4&at=10l6SU
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Free Android Phone app: https://play.google.com/store/apps/details?id=com.classdojo.android
Google Chrome app: https://chrome.google.com/webstore/detail/pbinoojbbajacmkigmfnkclhgjnglpon
Website: http://sites.google.com/
Free Android Phone app: https://play.google.com/store/apps/details?id=com.fusionprojects.edmodo
Free iPad app: http://itunes.apple.com/us/app/edmodo/id378352300?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/edmodo/id378352300?mt=8&uo=4&at=10l6SU
Website: http://www.edmodo.com/
Google Chrome app: https://chrome.google.com/webstore/detail/edmodo/fpcdidgjjebefhmlhjlgnkahlimgaemc
Website: http://screencast-o-matic.com/