There is a version of this review where I tell you that a sunscreen reminder app is unnecessary because the iOS Clock app does the same thing for free, and you should go install a two-hour repeating timer and close the App Store. I almost wrote that version. Then I tested REAPPLY for 18 days during a stretch of mixed weather, hotel rooms, two transit days, and one outdoor wedding, and I changed my mind partway through. The Clock app is not the same thing. It is close, but the difference is exactly where REAPPLY earns its install.
What REAPPLY is
REAPPLY is a free iOS and Android app whose single job is to tell you when to reapply sunscreen. It pulls the live UV index for your GPS location, takes your last logged sunscreen timestamp, factors in the time of day and the current solar angle, and returns a contextual reapply nudge. On a cloudy morning in Seoul in late autumn, the nudge spaces out further. On a clear summer noon in Lisbon, it tightens. The app also includes an educational section about UV index reading and a reef-safe sunscreen guide that recommends mineral-based formulas without specific brand placements. The basic loop is free with no ads. A few optional in-app purchases sit in the corner, none of them required.
Tool: sunscreen reapply tracker — tells you when to reapply based on UV index and activity.
Who it’s for
People who reapply inconsistently because the standard two-hour rule does not match their actual day. Commuters who are indoors more than out. Office workers near south-facing windows who get incidental UV exposure they forget about. Parents who reapply on kids and forget themselves. Anyone who has had a patch of unexplained hyperpigmentation and a dermatologist suggested chronic low-grade UV exposure was the cause. Not the right fit if you already reapply on a fixed schedule and remember without prompting, or if you are someone who finds notification fatigue worse than the original problem. The educational layer is genuinely calmer than most UV apps, which lean toward fear-bait. If you find the App Store’s UV index category exhausting, REAPPLY is the entry that does not shout.
Tool: hyperpigmentation type checker — differentiates PIH, melasma, and sunspots.
Features that matter
- Contextual reapply timing. Not a fixed 120-minute countdown. The app reads UV index, time of day, and your last log, and adjusts. This is the feature that justifies the install over a plain Clock alarm.
- Location-aware UV reading. Pulls live UV index data for your GPS coordinates. Works in transit. I tested it on a flight day across two cities and the index updated cleanly on arrival.
- One-tap log. Open the app, hit the reapply button, done. The friction is genuinely low. Most reminder apps fail at this step.
- Reef-safe sunscreen guide. Helpful as an editorial primer if you have not thought about oxybenzone and octinoxate, light on prescription-strength specifics. Not a reason to install on its own.
- Free, no ads, optional IAPs. The architecture is unusual. Most free SPF apps monetize aggressively. REAPPLY does not.
My contrarian take
The hard sell on a free sunscreen timer app is that your phone already has a Clock app, and the iOS Reminders app supports recurring location-aware alerts. For a flat two-hour reapply rule, the Clock app is genuinely equivalent. Where REAPPLY earns its install is the contextual part. A two-hour alarm on a cloudy December afternoon when you are indoors is noise. A two-hour alarm at the beach at 1pm in July is barely enough. The Clock app treats those identically. REAPPLY does not. That is the actual feature you are paying for, and you are paying with attention rather than money, since the app is free. The reef-safe section is editorial padding. The UV education content is good but you can get the same information from the SunSmart site or the Cancer Council. The single feature that does anything is the contextual nudge. If that is enough for you, install it. If it is not, the Clock app is fine.
Real-world test
I ran REAPPLY for 18 days starting in late April, across one wedding day with 5 hours outside, two transit days between cities, six normal commute days with maybe 40 minutes outside each, and three intentional cloud-cover tests where I sat near a window for two hours and logged whether the app pinged me. The wedding day was the strongest case. Standard two-hour alarm logic would have nudged me three times. REAPPLY nudged me five times because the UV index was high enough that the spacing tightened, and I appreciated the third one specifically because I had forgotten my hands. The transit days were where the location-awareness mattered: I landed in a higher-UV city and the next reapply nudge arrived sooner than my origin city schedule would have suggested. The cloud-cover test was where the contextual logic worked in the other direction: lower UV reading, longer interval, less nag. On the normal commute days, the app was quiet, which is the right behavior. I never felt notification-fatigued. The one-tap log felt low-friction enough that I actually used it. Most reminder apps fail this stage for me.
How it compares
SunSmart from the Cancer Council Australia is the editorial gold standard, free, with no commercial layer at all, and arguably more rigorous on the UV science. REAPPLY is friendlier and more reapply-focused. SunSafe adds a 10-day forecast and a tanning-progress mode that complicates the editorial position. The iOS Clock app does a fixed-interval version for free with zero install cost. If you want pure UV index data and education, SunSmart. If you want active reapply nudges tuned to context, REAPPLY. If you want a tanning workflow, SunSafe, with the asterisks I cover in the rest of the sun-uv-tools hub. For ingredient-level sunscreen decisions before purchase, pair REAPPLY with INCIDecoder or Cosmily.
FAQs
Is REAPPLY actually free? Yes. The core app is free, no ads, and the optional in-app purchases are not required for any feature I used in 18 days.
Is it better than a Clock app timer? Yes, if your day varies. The contextual UV reading is the reason. If your routine is identical every day, a fixed timer is fine.
Does it work indoors? The UV index reading factors in the time of day and the live UV value, but it cannot tell you are behind a window. If you spend significant time near south-facing glass, log a reapply manually and treat the nudges as a floor not a ceiling.
Is the reef-safe guide reliable? Useful as a primer. The brand recommendations are general. Cross-check against the Hawaii ban list if you care about specific filters.
What happens if I forget to log my first application? The contextual logic needs a starting timestamp. Without it, the app defaults to a two-hour schedule, which makes it equivalent to a Clock alarm. The one-tap log fixes this in two seconds.