Comparison

Satrelle vs Astrian Light

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

Head to head
About

Satrelle

Features
Read full description

On August 12, 2026, the moon's shadow crosses Spain at more than two thousand kilometers per hour. Satrelle tells you exactly when it reaches the spot where you're standing, to the second, computed on your phone, no signal required. FREE, A COMPLETE OBSERVER'S TOOL • Contact times C1-C4 for your exact position, from NASA Besselian elements, computed entirely on-device • Totality duration, sun altitude, and a live countdown • Set your site by GPS, on the map, or by typing coordinates • The 2026 and 2027 eclipses, plus future events • Works fully offline, in a field, on a mountain, anywhere THE PHOTOGRAPHER'S KIT, ONE PURCHASE, YOURS FOREVER Everything you use with a camera in your hands: • Exposure toolkit, Espenak tables computed for your aperture, ISO, and filter, with live atmospheric extinction for your sun altitude • Corona-pass fit, how many full bracket ladders your totality holds • Eclipse-day mode, timed voice callouts, camera-filter warnings, and T-minus haptics through all four contacts • Live Activity, the countdown on your lock screen and Dynamic Island • Rehearsal mode, practice your totality before you spend it • Site comparison, save candidate sites and compare their durations • Clock verification against NTP, contact times ride on your clock • Manual contact times from any limb-corrected site prediction The Kit is a single one-time purchase. It includes the August 2027 eclipse and every eclipse after it, it's shareable with your family, and every feature works with no connection at all. SAFETY Never look at the sun without ISO 12312-2 eclipse glasses. The only exception is totality itself, between second and third contact, and Satrelle tells you exactly when that is.

About

Astrian Light

Plan your celestial photography with precise calculations for eclipses, golden hour, and astrophotography. Visualize the sky's events with your real horizon and location data. Includes tools for hyperfocal distance and exposure.

Highlights
  • Eclipse shadow mapping
  • Real horizon calculations
  • Golden and Blue Hour timing
  • Sky object identification
  • Trip planning tools
  • Photography calculators
  • Camera and lens gear saving
Features
Read full description

Astrian Light Other apps tell you when the Sun rises. This one tells you whether you’ll actually see it. Astrian Light takes into account the real terrain at the place where you’re going to shoot — a mountain, a ridge, the horizon in front of you — and calculates when you’ll actually see the Sun appear. Not when it should rise over a flat horizon. When you’ll see it from where you’ll be. WHAT IT TELLS YOU · When the best light starts at your location and how long it lasts. · Whether the terrain will block the sunrise, and until when. · How many hours of dark sky you’ll have tonight based on the Moon. · When the Milky Way core will be visible and where it will appear. · What an eclipse will look like from your location and when each phase will happen. YOUR GEAR, INSIDE ASTRIAN Add your cameras and lenses once. From then on, the calculators work with your actual gear: pinpoint-star exposure, hyperfocal distance, depth of field, field of view, filters, and timelapse. If you use an adapter, Astrian automatically calculates the effective focal length. PLAN BEFORE YOU GO Compare locations and nights before deciding where to set up your tripod. Save each plan with its location, date, and the gear you’re taking. Once you’re there, your calculations will still be available even without a signal. ECLIPSES, FREE FOREVER Explore the map of every eclipse, see how much of the Sun will be covered from any location, check the complete timeline, and find out whether the terrain on your horizon will let you see it. Everything related to eclipses is free. Now and always. REAL DATA, EVEN WHEN DATA IS MISSING Astrian doesn’t fill in the gaps with estimates without telling you. If terrain data isn’t available for a location, Astrian will tell you that the calculation is using a flat horizon. If a weather forecast isn’t available, you’ll know that too. If Astrian can’t know something, it tells you. SUBSCRIPTION Astrian Light is free for planning eclipses and checking the sky from your current location. The annual subscription unlocks planning for any date and location, along with your gear and the rest of the advanced tools. The subscription renews automatically until cancelled and can be managed at any time from your Apple Account settings. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Satrelle4 screens
Astrian Light4 screens

Verdict

The call

The clearest difference is in-app purchases: Astrian Light at none against Satrelle's 1. Astrian Light also leads on update cadence (daily vs every 3 weeks). On price, ads, device support and iOS requirement 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. Satrelle sells 1 one-off in-app purchase. Astrian Light asks for nothing beyond the download.

UpkeepUpdate frequency

Satrelle ships an update every 3 weeks, Astrian Light daily. The most recent releases landed on September 29, 2026 and October 5, 2026 respectively.

Scorecard2 real differences · 8 level
Satrelle versus Astrian Light: the parameters behind the verdict, then further details
ParameterSatrelleAstrian Light
PriceFreeFree
Rating—5.0 (1 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—1 — better
Update frequencyEvery 3 weeksDaily — better
AdsNoNo
In-app purchasesYesNo — better
Monetization—Free
DevicesiPhoneiPhone, iPad — better
Requires iOS17.017.0
Further details — not scored
Size4 MB38 MB
Age rating4+4+
DeveloperHAND FORGED LLCJavier Linero

In-app purchases

1 purchases

Satrelle

One-time1
  • Photographer's Kit$9.99
None

Astrian Light

No in-app purchases

Questions

Is Satrelle free?
Satrelle is free to download, with in-app purchases available.
Is Astrian Light free?
Astrian Light is free to download, with no in-app purchases.
Do Satrelle or Astrian Light have ads?
Neither Satrelle nor Astrian Light shows ads.
Which is updated more often, Satrelle or Astrian Light?
Satrelle ships an update every 3 weeks, and Astrian Light daily. Most recently, Satrelle was updated on September 29, 2026 and Astrian Light on October 5, 2026.

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