In case this is useful for anyone, you can pay for our app using HSA/ FAS through our partnership with Flex: https://withflex.com/partners/stellar-sleep. There is a 7-day trial with the option of canceling anytime within the app itself. We also have a 30-day money-back guarantee, so if you decide at any point within 30 days that the program is not for you, you can get a full refund, no questions asked.