Hadalog: Skin Condition Log

Your skin moves with the weather and your habits. Hadalog turns a three-question check plus weather and health data into a picture of today and tomorrow.

Hadalog makes "why is my skin different today?" visible as an overlap of weather and daily habits. No camera, no photos of your face.

■ How it works Tap through three questions — tightness, oiliness, unsettledness — on a five-point scale. It takes about fifteen seconds. If you own a moisture meter, you can enter its readings instead. Weather (humidity, temperature, UV, wind) and Health (sleep, steps, water, cycle) are gathered automatically for the items you allow, and treated as that day's inputs. In the evening, one tap tells the app how it actually went, and the forecast moves closer to your own patterns. After fourteen days of records, it switches from general patterns to your own. Optional tags let you note what you saw — breakouts, redness, itchiness, dark spots, dullness. Register the products you use and you can later compare your average index on the days you used them against the days you did not. You can also record and check back from Apple Watch, and put today's index on a complication.

■ Free features ・Today's skin condition index ・Today's care suggestions ・Daily entries and records (unlimited) ・Product log ・Evening check-back ・Calendar and 7-day trend

■ With full access (one-time purchase) ・Tomorrow's forecast and suggestions ・Long-range trends, factor correlations, cycle phase ・Products and your index ・PDF export ・Local backup

■ Your data Your records and Health data never leave your device, and no account is needed. Only when fetching the weather is your location sent to Apple.

Full access is a one-time purchase. It is not a subscription — buy it once and it stays. Recording and today's index are free and unlimited.

Hadalog is a self-tracking app. It is not a substitute for medical diagnosis or care. If something concerns you and persists, please consult a dermatologist.