ScanSkinAI is a browser-based skin checker. You upload a photo, it screens the image against roughly 80 skin-condition categories, and you can pay for a dermatologist to review the result. It is explicit that this is preliminary screening and education rather than diagnosis, which is the right thing for a tool in that space to say.
The first thing worth being clear about: ScanSkinAI and Rosee Skin are built for different jobs. ScanSkinAI is looking at a mark or a patch and asking what it might be. Rosee is looking at your whole face and asking how your skin is doing week to week — hydration, texture, tone, redness — and what to change in your routine. If you have a mole or a lesion that worries you, neither app is the answer: see a doctor. If you want to screen something before you decide whether to book that appointment, ScanSkinAI is closer to what you want than Rosee is.
Where the two genuinely diverge is architecture. ScanSkinAI transmits your photo over an encrypted connection and processes it on a server. Rosee's face scan runs entirely on your iPhone — the image is analysed locally and then discarded, never uploaded. Encryption in transit is a real protection, but it is not the same thing as the photo never leaving the device, and for a face photo that distinction is worth understanding before you choose.