Assay: Acne & Skincare Tracker
Test If Your Skin Care Works
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Is your acne serum, retinol or moisturizer doing anything? Assay tests one product on your own face for 28 days and gives you a straight answer. Free while it is new.
You change five things at once. So you never learn which one worked. Assay changes one.
HOW IT WORKS
1. THE BASELINE: For the first 7 days you change nothing about your routine. That week is the baseline, and it is there because your face already moves on its own. It drifts with sleep, weather, stress, and overall health. Until you know how much your skin moves when nothing is happening, an after photo cannot tell you anything.
2. THE SCAN: Then you start the care product, and only that product. You log 1 photo a day, lined up with the camera guide so your framing stays put. Tests run for 28 days by default. You can run longer when the question needs it, anywhere from 21 to 182 days, because a spot treatment might work fast while a retinoid often looks worse at 4 weeks and better at 12.
3. THE LOCK: Assay measures three things in your daily photos: redness, texture, and evenness. On day 1 you pick what you are testing for, from acne, redness, texture, ageing, or just curious. That choice locks. It cannot be edited later. Picking which measure to report after you have seen what moved is how a test gets talked into a result it never produced.
THE VERDICT
At the end you get 1 of 4 answers:
* The product had a measurable effect.
* It had no measurable effect.
* It made things measurably worse.
* Inconclusive.
Inconclusive is a rule here, not a shrug. If you missed too many days, Assay says so and stops. It will not put a confident number on a fortnight of gaps, and it will not dress up a thin result to feel worth the wait. Most of the time it will tell you your product did nothing, because most of the time that is true.
THE RECEIPTS
You are asked what the product cost on day 1. When the verdict comes, it arrives next to that number.
PRIVATE BY DESIGN
Your photos never leave your device. All image analysis happens locally on your phone, and only your basic experiment text data syncs to your account.
Assay is for anyone who has spent real money on a serum and still has no idea whether it worked. Pick the product you are least sure about and start there.
Assay does not diagnose skin conditions and is not a substitute for a dermatologist.
Assay is free while it is new. There is nothing to buy inside it.
Terms of Use: https://getassay.pages.dev/terms
Privacy Policy: https://getassay.pages.dev/privacy
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
A clearer App Store page, so it is easier to see what Assay does before you download it.
Nothing has changed inside the app. You still pick the one product you doubt most, test it on your own face for 28 days, and get one of four answers: it worked, it did nothing, it made things worse, or there was not enough data to say.
Your photos still never leave your phone.
The developer, Ting Ting Xu, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Ting Ting Xu
- Size
- 71.3 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- Copyright
- © 2026 Starise