Works just fine, just read the instructions
All the bad reviews regarding ads are probably impatient people who don’t read instructions. The instructions could be a little more clear when you run a test, but if you read carefully it tells you a video will play so you can run tests ad free AFTER you watch an ad. This is no different than 90% of the free to use apps out there that have in-app ads. There is also a pretty clear visual warning stating that times will differ based on what iOS you are on as well. App works as expected and gave a decent analysis of wattage.