Tried to cancel and charged me anyway.
Response from developer
Hi kcr62, Thank you so much for your feedback regarding Light Meter Ultra and so sorry to hear you experienced an unexpected charge. Please feel free to reach out using the support link on our App Store product page or by tapping the support link in the app so that we can help you request a refund. In regards to the timing of charges: As Apple handle all transactions on our behalf, they also set the timing of when subscription fees are debited from customer accounts. Fees are debited according to the terms displayed on the system payment confirmation sheet that pops up when you agree to start a free trial and states that trials must be cancelled at least 24hrs before a trial ends to avoid a charge. You can review Apple's payment terms here https://support.apple.com/en-us/118428 . We hope this gives you some useful context around how fees are processed on the App Store. Best wishes, The Ultrafine Helpdesk Team.