We haven't started monetizing yet but we already announced our plans for Pro accounts. We've been lucky that our platform has been very popular in highschools, colleges, bootcamps across the world so we'll be charging for additional features hopefully soon.
I was looking everywhere for info on pricing, I suggest you mention this somewhere.
With the "create a free account" I thought I'd have to go through all the trouble of signing up before being faced with what I'd have to pay (looking at this as a teacher).
I found it surprisingly useful with my phone. But I couldn't edit the code using my regular keyboard (swiftkey), it did not add letters, only replaced the letter before the cursor, but it worked fine with the stock android keyboard. Haven't experienced that elsewhere.