Two thumbs, five seconds, and a number you will argue about.
A: Lay the phone between the two of you. Each person puts a thumb on the print at their end and holds it there for five seconds without pressing hard. The app reads the hold and gives you a Spark Score out of 100.
A: Your two names set a starting point, so the same pair always begins from the same number on any phone. The five-second hold then moves you off it, up or down, and the hold decides most of your score. It measures whether your thumbs landed together, whether you press in a similar way to each other, and how steady you both are. There is a full breakdown inside the app under "How it read" on any result.
A: No, and no. Thumbsparks is a game, not science. It cannot read fingerprints, because iPhones do not make fingerprint data available to apps at all. The prints on screen are targets to aim at. What it measures is real, though: hold it properly and you get a different number than if you fumble it.
A: A one-time $1.99 unlock, not a subscription. It adds a third point of contact to the game: hold hands, touch foreheads, link pinkies, whatever you can talk each other into. Scores then swing fifty percent further in both directions, so the best readings you will ever get are Extreme ones, and so are the worst. It does not make the reading more accurate.
A: Open the Extreme screen and tap "Restore purchase" at the bottom. That asks Apple to re-check your purchase history on the Apple ID signed in on the phone. If it is still locked, make sure you are signed in with the same Apple ID you bought it with, then email us and we will sort it out.
A: The reading needs both thumbs down for the whole five seconds. Lifting either thumb, or switching away from the app, ends it. Rest your thumbs on the prints rather than pressing hard, and try not to slide them around.
A: Open Past Reads and use the trash button in the corner. That clears everything the app has saved. Deleting the app removes it too. Nothing was ever sent anywhere, so there is nothing to delete on our end.