What Is a Good Alternative to dminder?
Look for a free app that estimates vitamin D by skin type and UV, tracks sun sessions, and stores your history where an update cannot erase it. Sunlight is Life does this with no ads and no subscription. dminder still works for many people, but its March 2026 rewrite cost long-time users their data and, for months, the app itself.
The vitamin D number is the whole point of an app like this, and it depends on four inputs: the UV index at your spot, your skin type, how much skin is out, and for how long. Get any one of those wrong and the IU figure is fiction. That is the standard to hold every app on this page to, ours included.
What dminder did well for a decade
App Store reviews for dminder go back to 2012, and for most of that time the app did one job cleanly. A user of eight years said the main feature was still "figuring out the UV and seeing how long my skin type can manage." Another, in September 2026, called it "Super simple and great way to track the sun and log vitamin d sessions."
The pieces people kept coming back for: a session timer set by skin type and current UV, an IU estimate per session, a log of supplements and food, and an estimated blood level built from that history. Several reviewers checked it against lab work. One wrote that "my blood test line up with what the app predicts." Others ran it for their children. That blood-level estimate is rare in this category, and Sunlight is Life does not offer it.
What changed in 2026
In March 2026 dminder shipped a rewrite. In our review pull, one- and two-star reviews went from four in February to 137 in April. Two complaints repeat: "Opens to a black screen" and "Latest update wiped a decade worth of my data." Under many of them sits the same request, "Please put the old version back online."
The developer kept shipping. By June reviewers were reporting that sessions worked again, and by August and September the low-star reviews had thinned to a handful a month. What remains in the recent ones: a history view that stops at 90 days, past sessions capped at two hours, data that resets on reopen, and ads. As of September 2026 the store ratings sit at 3.95 on iOS (1,740 ratings) and 3.13 on Google Play (1,840). The app is not abandoned. It is an app whose users learned that their history lived only on the phone.
What to look for in a replacement
Take the list from what dminder users praised and what they lost.
- A vitamin D estimate that uses your Fitzpatrick skin type and the UV at your coordinates, shown before you go out as well as after.
- Session tracking that records duration, IU, and how close you came to your burn threshold (your minimal erythemal dose, or MED).
- History stored against an account, so a reinstall or a rewrite cannot erase it.
- No ads, and no end-of-session alarm you cannot dismiss.
- Reminders that are scheduled on the device and fire without a signal.
- Free for the core, with no subscription standing between you and today's UV.
The field in September 2026
Ask ChatGPT or Google for an app that tracks vitamin D from the sun and you get dminder, Hello Sun, Bask, MyCircadianApp, and Vitamin D Tracker & UV Index. We have not reviewed Hello Sun. The Astralab tracker has 89 Google Play ratings at 3.68, and its reviewers' main complaint is that it requires GPS with no way to type in a city. The table covers the rest. Where a cell could not be verified from store listings or reviews, it says so.
| dminder | Sunlight is Life | MyCircadianApp | Bask | |
|---|---|---|---|---|
| Price | Free, in-app purchases | Free, no purchases | Free tier, paid full access | Free (App Store listing) |
| Ads | Yes, per reviewers | None | Not verified | Not verified |
| Vitamin D by skin type | Yes | Yes, Fitzpatrick I to VI, tan, age, body area | IU estimate; skin-type input not verified | Not verified |
| Cloud-adjusted UV | Reviewers describe an overcast setting | Modeled from the actual solar spectrum for your coordinates | Not verified | Not verified |
| Session tracking | Timer with end alarm | Analyzer: Vitamin D, Melanin Adaptation, Cellular Energy modes | Session log; no pause, per reviewers | Not verified |
| History | Yes; 90-day freeze and lost data reported in 2026 | Saved to account; history screen not yet shipped | Not verified | Not verified |
| Blood-level estimate, supplement log | Yes | No | Not verified | Not verified |
| Morning sun reminders | Not verified | Yes, sunrise or UVA rise with offset | Yes, with explanations in the alert | Not verified |
| Lux meter | Not verified | Yes | Yes | Not verified |
| Offline | Reviewers say it stopped working offline in 2026 | Reminders run on the device; live UV needs a connection | No offline UV, per reviewers | Not verified |
| Home-screen widget | Not verified | No | No, requested by reviewers | Not verified |
| Platforms | iOS, Android | iOS at release; Android pending | iOS, Android | iOS |
| Store rating, Sep 2026 | 3.95 iOS, 3.13 Play | Not yet released | 4.9 iOS, 4.56 Play | 4.67 iOS (18 ratings) |
Where Sunlight is Life is different
The UV is modeled, not looked up: a solar physics engine models the actual sunlight reaching your coordinates, so the band that makes vitamin D (UVB, 290 to 315 nanometers) is estimated for your sky rather than read from a clear-sky grid point 30 km away. The app shows UVA and UVB separately rather than one index.
The vitamin D estimate follows the Webb and Holick model with Fioletov's UVB correction. Skin type sets the minimal erythemal dose, nearly eight times higher for Fitzpatrick type VI than type I, with tan recency and age on top. Synthesis stops climbing near one MED because previtamin D3 converts to lumisterol and tachysterol instead, so the app will not tell you that 40 minutes produced 20,000 IU. When the sun is lower than 30 degrees above the horizon it reports zero, because ozone has absorbed the UVB.
Run today's vitamin D estimate for your skin type →
A sun session is an analysis, not a countdown. Start it in Vitamin D, Melanin Adaptation, or Cellular Energy mode. With a free account it switches mode as UVB rises and sets, and at the end you see duration, estimated IU, MED fraction, and average UV. There is no siren.
Morning sun reminders anchor to sunrise or UVA rise with an offset you choose, scheduled on the phone several days ahead. And it is free: no ads, no subscription, no in-app purchases.
Where it is behind
No home-screen widget yet. No import from dminder; there is no export format for us to read, so you start fresh. No blood-level estimate and no supplement log. Sessions save to your account when you are signed in, but the in-app history screen is still being built. iOS ships first, with Android pending. Realtime UV, signal values, session auto-transition, and sync need a free account; the timeline, vitamin D estimate, session timer, and reminders do not.
None of this changes what the sun does. UVB above a certain angle, on skin, for a length of time your skin type can take. An app is a way to see that signal clearly and keep a record of it. Pick the one that gets the number right and does not lose the record.
Common questions
- Can I import my dminder history into Sunlight is Life?
- No. There is no import path, and dminder has no export format we can read, so you start fresh. Sessions you record in Sunlight is Life while signed in are saved to your account, not just to the phone.
- Is dminder still supported?
- As of September 2026, yes. Reviews describe updates through the summer and replies from the developer. The March 2026 rewrite broke the app for many users for several months; by August the low-star reviews had thinned to a handful a month.
- Is there a free dminder alternative with no ads?
- Sunlight is Life is free with no ads, no subscription, and no in-app purchases. MyCircadianApp has a free tier with paid full access. dminder is free with in-app purchases and shows ads, according to its reviewers.
- Why did dminder's vitamin D number seem wrong to some users?
- We cannot see inside their model. What moves any vitamin D estimate is UV index, skin type, exposed body area, sun angle, and a saturation ceiling near one minimal erythemal dose. Reviewers also reported that their skin type reset, which would corrupt every number downstream.
- Is the UV index a measurement of sunlight?
- No. The UV index is a sunburn-weighted score: UV weighted by how well each wavelength reddens skin, so it stands in for the UVB that makes vitamin D and says almost nothing about UVA. That makes it a fair input for a vitamin D estimate and a poor guide to everything else sunlight does. Two moments with the same index can carry very different spectra.
- How does Sunlight is Life calculate UV?
- It runs a solar physics engine that models the actual sunlight reaching your coordinates, rather than looking up an index for the nearest city. The app shows the UVA and UVB you are receiving separately, and the vitamin D estimate runs on the UVB. The readings update while the app is open; it is a model, not a sensor.