Tress

There is no account, no sign-in and no server of ours. Your photographs, notes and routine live in the app’s private storage on your own phone. No part of the app uploads them, so your photographs are not ours to see.

They are read on the phone, by the phone. The models that read a picture ship inside the app — one helps line the shot up, another measures how much of the frame your hair covers. The picture goes in, a few numbers come back, and the picture stays where it is.

Some things do leave, and the privacy policy takes them one at a time: when you scan a product, its barcode digits go to Open Beauty Facts and its picture comes back; on iPhone, opening the subscription screen — the paywall — asks our subscription provider about this install, as do buying and restoring, and once there is a membership to keep track of the app asks again when the answer it has stored has run out of date; anything you send from the share sheet goes where you send it, and an update sheet has your photographs in it; and a device backup, if you have one turned on, carries the photograph files off the phone.

No photograph and nothing you write is part of the barcode lookup or the subscription check. And if you never open the subscription screen and never buy, that check does not happen: an install that has not been near the price is not one our subscription provider has heard of.