Comparison

SoHO Viewer vs Project Planet Space

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

Head to head
About

SoHO Viewer

Access and view the latest images from the Solar and Heliospheric Observatory (SoHO). Receive push notifications when new images are available, keeping you updated on solar activity. This app is a convenient tool for anyone interested in space imagery.

Highlights
  • Download latest SoHO images
  • Display solar images
  • Push notifications for new images
  • Badge notification for new images
  • Image courtesy of SOHO consortium
Features
Read full description

SoHO Viewer is a simple application for downloading and displaying the latest images taken by the Solar and Heliospheric Observatory (SoHO). It includes push notifications so you can be notified by a badge on the application when new images are available. It was quoted as “one of the ten best free applications to have on your iphone if you like stargazing:” http://www.networkworld.com/news/2010/112210-free-iphone-stargazing-apps.html It appears in Mars 2015 edition of Sky And Telescope, page 70. Images are courtesy of SOHO consortium. SOHO is a project of international cooperation between ESA and NASA. If you had like to see images taken by Solar Dynamics Observatory (SDO) please use the SDO Viewer application.

About

Project Planet Space

Features
Read full description

Project Planet - an interactive map of our solar system How much would you weigh on Jupiter? Why does a day on Mercury last longer than its year? Project Planet turns space facts into a fingertip-sized journey. Scroll through all nine planets (Pluto included), feel each world's pull on your own body, and explore the numbers astronomers have spent decades collecting. Highlights - Sticky scroll across the system: from Mercury to Pluto, each planet stays centred long enough for you to take it in. - You, on every world: enter your weight and age once and watch them recalculated by each planet's gravity and orbital period. - Five rich widgets per planet: surface temperature with reference markers (Antarctica, freezing, boiling), atmospheric pressure with composition chart, travel times from Earth from walking up to the speed of light, gravitational force with everyday objects (phone, backpack, car), and an interactive pressure simulator with phase changes for water, oxygen, CO2, hydrogen, nitrogen and mercury (Antoine equation under the hood). - Six languages: Czech, English, German, Slovak, Spanish and French, auto-detected from your device. - Metric or imperial: switch instantly; weights, temperatures and distances follow your preference. - Crafted to feel like a small cosmic museum: dark cosmic theme, hand-tuned typography, subtle scroll choreography, and a right rail that lets you jump to any planet. - Built on real data: gravitational accelerations, orbital periods, NASA mean temperatures, atmospheric compositions and substance phase transitions. Requires an internet connection. The app runs as a continuously updated webview and uses native iOS capabilities such as haptic feedback to add a tactile dimension to your interstellar journey.

Screenshots

SoHO Viewer4 screens
Project Planet Space4 screens

Verdict

The call

The clearest difference is update cadence: SoHO Viewer at every 2 months against Project Planet Space's every 25 months. SoHO Viewer also leads on iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

SoHO Viewer ships an update every 2 months, Project Planet Space every 25 months. The most recent releases landed on October 13, 2026 and September 30, 2026 respectively.

Scorecard2 real differences · 8 level
SoHO Viewer versus Project Planet Space: the parameters behind the verdict, then further details
ParameterSoHO ViewerProject Planet Space
PriceFreeFree
Rating3.4 (19 ratings) — better—
Positive reviews69.1% of reviews—
Number of ratings19 — better—
Update frequencyEvery 2 months — betterEvery 25 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size5 MB2 MB
Age rating4+4+
DeveloperJérôme DiazMiroslav Hanzelka

In-app purchases

None

SoHO Viewer

No in-app purchases

None

Project Planet Space

No in-app purchases

Questions

Is SoHO Viewer free?
SoHO Viewer is free to download, with no in-app purchases.
Is Project Planet Space free?
Project Planet Space is free to download, with no in-app purchases.
Do SoHO Viewer or Project Planet Space have ads?
Neither SoHO Viewer nor Project Planet Space shows ads.
Which is updated more often, SoHO Viewer or Project Planet Space?
SoHO Viewer ships an update every 2 months, and Project Planet Space every 25 months. Most recently, SoHO Viewer was updated on October 13, 2026 and Project Planet Space on September 30, 2026.

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