After doing some research, I see that banks and software give people the ability to give their bookkeepers or accountants read-only access to their accounts. I'm guessing that the business clients of Ewasko did this because there would be no need to allow permission to make payments.
It looks like Turbotax does not have this feature for accountants, but in theory an accountant with client could call the IRS on speaker phone to verify profit. Obviously if the accountant filed taxes for the client, then he or she would have access to the information.
So I can't see anything that is clearly suspicious, just that the compensation is partially based on increasing profit, not completely: "We defer a portion of our program costs, activating them only when you reach the targeted net operating income for a given year, as stated in your tax returns." That's a different statement than "You make your profit or we don’t make ours." on the main page. I'm not sure how a conditional and delayed authorization of payment works. The word "activating" sounds electronic and not just an old fashioned paper check and a contract that can be enforced legally.