How I Use It
I have used it in class to prepare students before the ACT test, and they liked it. Some students kept using it afterwards, and when their free trial ran out they created a new account with a different email address. This seems like its bending the rules, but I'm not sure I would recommend students pay for the full account. The downside is with a trial account a student can't keep track of their progress.
At our school we are 1-to-1 with iPads, so I have had students log in to Grockit during class and join a group study session. The first 9 (or 10? can't remember) students get grouped together, then the next 9 and so forth. So, the downside is that some groups may end up being very small. Once they get started they tend to get impatient waiting for everyone to answer so they start giving hints about how to do the problem. That's great! When a student has to explain how to do a problem they learn it better themselves and there's a win-win. I just have to make sure to coach them not to "give away" the answer. I sign in to their study sessions, too, so I can keep track of their progress.
Although I haven't assigned Grockit as homework outside of class, I have often recommended to students, whenever they ask me how to study for the math portion of the ACT or SAT.
This is a great study aid for standardized test prep. I like the group study sessions. Students receive instant feedback about problems. There isn't a lot of content delivery, mainly just assessment, as expected. I sometimes log in to the group study sessions as a teacher just to help students who happen to be logged in - even though they aren't "my" students. There is a chat feature, and when they get stuck I give them hints about the problems. I think of it as community service, and it's actually quite fun! The students who are logged in have always said they learned a lot. I recommend this site any time a student needs a good resource that's free to study for the ACT or SAT. You can get a lot out of the free trial but I suppose if you had the money the paid account would be better. I have never spent the money.