Comparison

Slather vs SunSync

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Slather

Features
Read full description

Slather reminds you when to reapply sunscreen — so you stay protected without watching the clock. It checks the live UV index for your exact location, you pick your SPF, and Slather counts down to your next reapplication, sending a reminder the moment it's time. • Live UV index for your location (via Apple WeatherKit) • Pick SPF 15 / 30 / 50 / 50+ — the reapply window adjusts to match • A clear countdown with a reminder when it's time to reapply • Live Activity on your Lock Screen and Dynamic Island • Apple Watch app + complications — glance at the UV and reapply, or start a session, from your wrist • UV-exposure history, with optional sync to Apple Health • Light and dark mode Slather asks for Location (to look up your UV) and Notifications (for reminders). There's no account, no ads, and no tracking — your data stays on your device. Heads up: the UV index reads 0 (Low) at night or indoors — that's correct, not a bug. Step outside in daylight to see a real reading. Slather Premium (optional) Everything above is free — live UV, SPF timing, reapply reminders, the Live Activity, the Apple Watch app, and Apple Health sync. Premium adds two extras: • Family profiles — track SPF and reapply timers for everyone you protect • Weekly insights — your sessions, protection time, and strongest sun days • Slather Premium — $4.99 per year, starting with a 7-day free trial • Slather Premium Lifetime — $14.99, a one-time purchase Payment is charged to your Apple Account at confirmation of purchase. A subscription renews automatically unless it is canceled at least 24 hours before the end of the current period, and your account is charged for renewal within 24 hours of the end of that period. You can manage or cancel your subscription in your Apple Account settings after purchase. Any unused portion of a free trial is forfeited when you purchase a subscription. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://scotch333.github.io/slather-legal/

About

SunSync

This app helps you stay safe in the sun by providing local UV index information, smart sunscreen reapplication timers, and gentle reminders. It personalizes your sun protection based on your skin type and activity, turning sun safety into a simple daily ritual.

Highlights
  • Local UV index readings
  • Smart sunscreen reapply timer
  • Personalized sun protection
  • Gentle reapply reminders
  • UV alerts with quiet hours
  • Home/Lock Screen UV widget
Features
Read full description

Stay in the sun, safely. SunSync is a calm, wellness-first sun companion for iPhone and Apple Watch. It reads the UV where you are, paces your sunscreen with a smart reapply timer, and turns sun safety into a thirty-second ritual you'll actually keep. No app replaces sunscreen — SunSync helps you remember it, reapply on rhythm, and understand your exposure. KNOW YOUR SKY • Local UV index for your exact location, powered by Apple Weather • Today's peak UV hours, cloud cover, temperature, and sunset • A glowing protection ring that answers the only question that matters: am I still covered? THE APPLY RITUAL — FOUR TAPS, THEN BACK OUTSIDE • Pick a saved sunscreen, or set up in seconds: SPF, activity (beach, run, hike, pool, and more), and water resistance • A smart reapply timer tuned to your SPF, activity, skin type, and the live UV — not a flat two hours • A gentle "still outside?" check when your protection runs low, so your exposure stays accurate REMINDERS THAT RESPECT YOU • Reapply reminders and UV alerts, with quiet hours so you're never pinged at night • Tap "Reapply" right from the notification PERSONAL TO YOUR SKIN • Set your Fitzpatrick skin type and everyday SPF during a quick setup • Your profile syncs to your account, so it's there when you sign in on a new device WHAT'S INCLUDED FREE • Daily UV index and protection ring • The apply ritual and smart reapply timer • Reapply reminders and UV alerts • A Home Screen / Lock Screen UV widget • One saved sunscreen SUNSYNC PLUS Go further with a 7-day free trial: • Live UV that refreshes as conditions change and when you travel • Full insights — your weekly protection score, year-long trends, and complete session history • Unlimited sunscreen profiles • Apple Watch app — start, track, and reapply from your wrist, plus a watch-face complication • Protection-timer widgets for your Home Screen and Lock Screen PRIVACY No ads. We never sell your data. Your location is used only to retrieve the UV index for where you are. SunSync is free to try — full access starts with a 7-day free trial of SunSync Plus (yearly, auto-renews, cancel anytime); a free tier is available after your trial" SUBSCRIPTION SunSync Plus is an auto-renewable subscription. • Pricing: $1.99/month or $14.99/year (may vary by region) • New subscribers get a 7-day free trial • Payment is charged to your Apple Account at confirmation of purchase • Your subscription renews automatically unless canceled at least 24 hours before the end of the current period • Manage or cancel anytime in your Apple Account settings • Any unused portion of a free trial is forfeited when you purchase a subscription SunSync is a wellness tool, not a medical device. It does not replace sunscreen, protective clothing, shade, or professional medical advice. UV readings and timers are estimates and may not be accurate. Always follow your sunscreen's directions. Terms of Use: https://sunsync-bda19.web.app/terms Privacy Policy: https://sunsync-bda19.web.app/privacy

Screenshots

Slather4 screens
SunSync4 screens

Verdict

The call

The clearest difference is in-app purchases: Slather at none against SunSync's 2. SunSync's advantage is update cadence (fortnightly vs every 2 months) and iOS requirement (18.6 vs 26.0). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. SunSync sells 2 in-app purchases, starting at $1.99 per month. Slather asks for nothing beyond the download.

UpkeepUpdate frequency

Slather ships an update every 2 months, SunSync fortnightly. The most recent releases landed on September 29, 2026 and October 5, 2026 respectively.

Scorecard3 real differences · 7 level
Slather versus SunSync: the parameters behind the verdict, then further details
ParameterSlatherSunSync
PriceFreeFree
Rating—4.0 (2 ratings) — better
Positive reviews—50.0% of reviews
Number of ratings—2 — better
Update frequencyEvery 2 monthsFortnightly — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPad, Apple WatchiPhone, iPad, Apple Watch
Requires iOS26.018.6 — better
Further details — not scored
Size9 MB30 MB
Age rating4+12+
DeveloperDavid PriceSamuel Araya

In-app purchases

None

Slather

No in-app purchases

2 purchases

SunSync

Subscriptions2
  • SunSync Plus Monthly$1.991 Month
  • SunSync Plus Yearly7 Days trial$14.991 Year

Questions

Is Slather free?
Slather is free to download, with no in-app purchases.
Is SunSync free?
SunSync is free to download, with in-app purchases available.
Do Slather or SunSync have ads?
Neither Slather nor SunSync shows ads.
Which is updated more often, Slather or SunSync?
Slather ships an update every 2 months, and SunSync fortnightly. Most recently, Slather was updated on September 29, 2026 and SunSync on October 5, 2026.

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