The "very clear about the fact it cannot detect a heart attack" thing is so obnoxious that it actually kinda breaks that app. If you got a messy/noisy EKG reading and want to do it again, you have to carefully scrooll to the bottom of the page and click done. Or you accidentally tap the large grey box at the top that takes you to a multi-page legal explanation of how it's not meant to detect a heart attack - and that page has a teeny tiny button at the top left to take you back to the last page.