Each of these allows you to create “whiteboard” style videos. Some are more complex than others.
Free iPad app: https://itunes.apple.com/us/app/id412443803?mt=8&at=10l6SU
Paid Windows program: https://doceri.com/win_doceri.php
Paid Mac program: https://doceri.com/download_form.php
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
Free iPad app: https://itunes.apple.com/us/app/educreations-interactive-whiteboard/id478617061?mt=8&at=10l6SU
Free iPad app: http://itunes.apple.com/us/app/teach/id527216211?mt=8&uo=4&at=10l6SU
Free iPad app: http://itunes.apple.com/us/app/screenchomp/id442415881?mt=8&uo=4&at=10l6SU
Free iPad app: https://itunes.apple.com/us/app/ask3/id572042047?mt=8&uo=4&at=10l6SU