The calculators and the reference library are the part of CogoKit that is useful on a Tuesday afternoon, and they are free forever. Premium is for the part you come back to repeatedly: 330 practice questions across every subject area and 61 problems worked end to end.
Every calculator, the whole reference library and all the guides are free to use forever - the practice bank, the full problem library and the printable job paperwork are the paid upgrade.
Plans
Questions
What stays free?
All 10 calculators, the whole 61-page reference library and every guide - permanently, with no account. On top of that, a fresh round of 8 practice questions is free every day, and 8 solved problems from across the categories are free to read in full.
How is my access stored?
Web purchases are tied to the browser you buy in, using an anonymous purchase id kept in this browser's local storage. There is no account and no password. Once you subscribe, this page shows that id as an access code - save it, and you can move your Premium to any other browser or device.
I bought Premium in another browser. How do I get it here?
Paste your access code on the restore page. If the code carries an active subscription, Premium moves to this browser immediately.
Lost your code?
Reply to your purchase receipt email from the address you paid with - your subscription is tied to it and access can be recovered from there.
Can I cancel?
Yes, at any time, from the link in your receipt email or from the billing portal shown on this page once you are subscribed. A lifetime purchase is a one-time payment and does not renew.