Free apps available via the Chrome browser.
Google Chrome app: https://chrome.google.com/webstore/detail/bhdheahnajobgndecdbggfmcojekgdko
Website: https://www.desmos.com/
Edmodo app: http://www.edmodo.com/publisher?uid=3382251
Free iPad app: https://itunes.apple.com/us/app/graphing-calculator-by-desmos/id653517540?mt=8&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/graphing-calculator-by-desmos/id653517540?mt=8&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.desmos.calculator
Free Android Tablet app: https://play.google.com/store/apps/details?id=com.desmos.calculator
Google Chrome app: https://chrome.google.com/webstore/detail/diigo-bookmark-archive-hi/oojbgadfejifecebmdnhhkbhdjaphole
Mozilla Firefox extension: https://addons.mozilla.org/en-US/firefox/addon/diigo-web-highlighter-and-stic/
Free iPad app: https://itunes.apple.com/us/app/diigo/id417202559?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/diigo-offline-reader/id335006600?mt=8&uo=4&at=10l6SU
Website: http://www.diigo.com/
Website: http://duolingo.com/
Google Chrome app: https://chrome.google.com/webstore/detail/duolingo/aiahmijlpehemcpleichkcokhegllfjl
Website: http://www.easybib.com/
Free iPhone app: http://itunes.apple.com/us/app/easybib/id436768184?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.easybib.easybibandroid
Google Apps for Education app: https://www.google.com/enterprise/marketplace/viewListing?productListingId=6357+7423325443125160988
Google Chrome app: https://chrome.google.com/webstore/detail/cbpiiblghhnlalifiaddecedaeaijdpe
Website: http://www.mindmeister.com/
Free iPad app: http://itunes.apple.com/us/app/mindmeister-for-ipad/id381073026?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/mindmeister-mind-mapping/id291226775?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.meisterlabs.mindmeister
Google Apps for Education app: https://www.google.com/enterprise/marketplace/viewListing?productListingId=3435+15475579680845921511
Google Chrome app: https://chrome.google.com/webstore/detail/mindmeister/bdehgigffdnkjpaindemkaniebfaepjm
Free Android Tablet app: https://play.google.com/store/apps/details?id=com.meisterlabs.mindmeister
Website: http://www.picmonkey.com/
Google Chrome app: https://chrome.google.com/webstore/detail/picmonkey/fgdgokchhicmaiacmgegjnppjkgogdhm
Facebook app: https://apps.facebook.com/picmonkey/
Website: http://www.powtoon.com/
Google Chrome app: https://chrome.google.com/webstore/detail/powtoon-edu/ogodblbnhpbcmcjcoopbalconhnloagl
Google Chrome app: https://chrome.google.com/webstore/detail/eglmnheeacbdmbfglhdblefapoebeifj
Website: http://www.screenleap.com/
Website: https://trello.com/
Free iPhone app: https://itunes.apple.com/us/app/trello/id461504587?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.trello
Google Chrome app: https://chrome.google.com/webstore/detail/trello/oflhioojkbelepjlnafgmgkkjhojphcg
Google Chrome app: https://chrome.google.com/webstore/detail/gajclnhcflhoicggnpmgkedchldikjgn
Free iPad app: http://itunes.apple.com/us/app/voicethread/id465159110?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/voicethread/id465159110?mt=8&uo=4&at=10l6SU
Website: http://voicethread.com/
Free Android Phone app: https://play.google.com/store/apps/details?id=air.wevideo.camera
Google Chrome app: https://chrome.google.com/webstore/detail/okgjbfikepgflmlelgfgecmgjnmnmnnb
Website: http://www.wevideo.com/