Comparison

MARSS vs Eclipse Countdown

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

Head to head
About

MARSS

Features
Read full description

MARSS inaugura una nuova modalitΓ  di visita in RealtΓ  Aumentata del MusAB - Museo Astronomico di Brera; con le nuove tecnologie digitali gli strumenti della Galleria vi accompagneranno in un viaggio alla scoperta del loro legame con la storia, la cittΓ  e le frontiere dell’astronomia. L’esperienza di visita, coinvolgente ed interattiva Γ¨ stata realizzata grazie ad un finanziamento di Fondazione Cariplo, alle competenze del Politecnico di Milano e alle conoscenze dell’INAF – Osservatorio Astronomico di Brera; Stiamo ancora migliorando l'app e correggendo i bug che ci segnalate

About

Eclipse Countdown

This astronomical tool provides precise sub-second solar eclipse timings and interactive maps. It guides users through the eclipse experience with real-time calculations, audio cues, and a list of phenomena to observe.

Highlights
  • Precision timing engine
  • Interactive mapping
  • Live audio synchronization
  • List of phenomena to observe
  • Lunar limb profile corrections
  • 3D computational models
Features
Read full description

The Eclipse App is a high-fidelity astronomical tool engineered for observers who demand absolute accuracy as well as beginners who need a guide through the exceptional experience of their first total solar eclipse. Powered by the latest 3D computational models developed by the Besselian Elements Team, this App provides accurate sub-second eclipse contact timings using lunar limb profile corrections. Whether you are a professional researcher, an astrophotographer, or a dedicated eclipse chaser, this app provides the rigorous data necessary for a successful expedition, from interactive map useful for planning, to simulating the countdown and exercise with the equipment, and for real time tracking in case you are moving in search of the right spot. Core Features: β€’ Precision Timing Engine: Real-time calculations of Contact Times based on your exact GPS coordinates β€’ Interactive Mapping: High-resolution path-of-totality overlays including umbral limits an the center-line. The IQP method accounts for the topography on both the lunar limb and at the observer site, as well as relying on an improved value for the eclipse solar radius (959.95" Β± 0.05", based on research by the Besselian Elements Team). The eclipse center-line and the northern and southern limits of the umbral shadow path also account for these three factors. Hence, these lines are not smooth lines, as in most publicly-available eclipse maps, but are noticeably jagged. Two lines are presented at each path limit corresponding to two values of the eclipse solar radius (959.90" and 960.00") in order to display a region of uncertainty rather than a single limit line. β€’ Live Audio Synchronization: A sophisticated voice-cue system that announces critical contact phases and astronomical phenomena (e.g., shadow bands, corona visibility, and solar filtration changes), allowing you to keep your eyes on the sky or your equipment. β€’ List of phenomena to observe during the eclipse at every step, so that you can be reminded to watch at the right time Designed for the Rigorous Observer: The Eclipse App eliminates the margin of error inherent in simplified models. Prepare for the next Great Eclipse with the most scientifically robust tool available on the App Store.

Screenshots

MARSS2 screens
Eclipse Countdown4 screens

Verdict

The call

The clearest difference is price: MARSS at Free against Eclipse Countdown's $1.99. MARSS also leads on update cadence (every 5 days vs monthly) and iOS requirement (12.0 vs 15.1). On ads, in-app purchases and device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

MARSS is free to download; Eclipse Countdown costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

MARSS ships an update every 5 days, Eclipse Countdown monthly. The most recent releases landed on October 9, 2026 and October 14, 2026 respectively.

Scorecard3 real differences Β· 5 level
MARSS versus Eclipse Countdown: the parameters behind the verdict, then further details
ParameterMARSSEclipse Countdown
PriceFree β€” better$1.99
Positive reviewsβ€”100.0% of reviews
Update frequencyEvery 5 days β€” betterMonthly
AdsNoNo
In-app purchasesNoNo
Monetizationβ€”Paid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 β€” better15.1
Further details β€” not scored
Size257 MB49 MB
Age rating4+4+
DeveloperINAF Osservatorio Astronomico di BreraBESSELIAN ELEMENTS PTY LTD

In-app purchases

None

MARSS

No in-app purchases

None

Eclipse Countdown

No in-app purchases

Questions

Is MARSS free?
MARSS is free to download, with no in-app purchases.
Is Eclipse Countdown free?
Eclipse Countdown costs $1.99, with no in-app purchases.
Do MARSS or Eclipse Countdown have ads?
Neither MARSS nor Eclipse Countdown shows ads.
Which is updated more often, MARSS or Eclipse Countdown?
MARSS ships an update every 5 days, and Eclipse Countdown monthly. Most recently, MARSS was updated on October 9, 2026 and Eclipse Countdown on October 14, 2026.

Other comparisons