I signed up for an Instagrok account this summer but didn’t realize what a great tool it was until now. And lucky for me, those who already had accounts, do not have to pay $35 a year for it this year.
There are some videos that explain how you can use it. It is a web site. It is supposed to be able to be linked with Edmodo but so far I have not been given access to the Edmodo App Store to get it. I think it is because I’m in Taipei.