Freemium You may recall INSTAGROK from our Best of S'cool Tools Q1 2012 list. Since then the Grok squad has added a number of standard and premium features including custom concept maps, search history, and embedded journals for easy note-taking. For $35 educators can also utilize a teacher dashboard, content filtering, ad-free searches, and even integrated Edmodo assignments. Instagrok CEO Andrew Bender tells EdSurge that the user base expanded more than 30% in March alone, largely due to word-of-mouth recommendations from teachers. For a good chuckle, check out some of the user-generated key facts on the this Common Core grok.