Free iPad app: https://itunes.apple.com/us/app/subtext/id457556753?mt=8&ign-mpt=uo%3D4&uo=4&at=10l6SU
Edmodo app: http://www.edmodo.com/publisher/subtext
Paid iPad app: https://itunes.apple.com/us/app/id431493086?mt=8&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/id431493086?mt=8&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.explaineverything.explaineverything
Free Android Tablet app: https://play.google.com/store/apps/details?id=com.explaineverything.explaineverything
Google Chrome app: https://chrome.google.com/webstore/detail/explain-everything/abgfnbfplmdnhfnonljpllnfcobfebag
Website: http://www.thinglink.com/
Free iPad app: https://itunes.apple.com/us/app/thinglink/id647304300?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/thinglink/id647304300?mt=8&uo=4&at=10l6SU
Free iPad app: https://itunes.apple.com/us/app/chromville/id748017957?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/chromville/id748017957?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.imascono.proyecto_dibujar
Free iPad app: https://itunes.apple.com/us/app/adobe-voice-show-your-story/id852555131?mt=8&uo=4&at=10l6SU