DLR COMETS vs Number Line
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DLR COMETS
Explore the Rosetta mission to Comet 67P/Churyumov-Gerasimenko through an interactive exhibition. Discover the science behind comets and the historic Philae lander touchdown. Relive this exceptional spaceflight adventure with multimedia content.
- Interactive comet model
- Mission highlights and photographs
- Historical background on comets
- Rosetta mission science
- Philae lander touchdown details
- Personal stories from the mission
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The European Rosetta mission arrived at Comet 67P/Churyumov-Gerasimenko in August 2014 after a 10-year journey through space. Three months later, the Philae robotic lander touched down on the comet – the first probe to do so in the history of humankind. It was a fantastic scientific adventure and an exceptional spaceflight project. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) takes you on a journey to the origins of the Solar System with this exhibition app “DLR COMETS - The Rosetta mission: Journey to the origin of the Solar System”. The centrepiece of the exhibition is a model of comet 67P/Churymov-Gerasimenko based on data from Rosetta’s OSIRIS camera system, surrounded by backlit photographs of the comet and mission highlights. Additionally to the historical and technical background on comets as important building blocks of the Solar System, the Rosetta mission and its scientific achievements to date, the exhibition includes film-clips highlighting the personal stories of the men and women that made Rosetta a reality and the deep emotions evoked by involvement in the mission.
Number Line
This app provides an interactive number line for educational purposes, enabling users to visualize numbers, perform various math games, and practice rounding. Its simple interface supports zooming, swiping, and marking numbers with pins or freehand drawing.
- Infinite number line visualization
- Rounding practice (nearest 10, 100, 10,000)
- Number comparison
- Pinch-to-zoom functionality
- Swipe navigation
- Search for specific numbers
- Pin marking
- Freehand drawing tool
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An infinite number line to use in the classroom, with a simple design that allows for numerous maths games and challenges! • Ask the class to round to the nearest 10/100/10,000. • Visualise the size of numbers relative to one another, including negatives. How to use: • Zoom with a pinch • Swipe along the number line • Go to a number by typing in the search box • Drag and drop pins to mark numbers • Draw free-hand with the pen tool
Screenshots
Verdict
The clearest difference is review sentiment: Number Line at 100% against DLR COMETS's 0%. DLR COMETS's advantage is update cadence (every 3 weeks vs every 15 months) and iOS requirement (8.1 vs 13.0). On price, ads, in-app purchases and monetization model 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
DLR COMETS ships an update every 3 weeks, Number Line every 15 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.
| Parameter | DLR COMETS | Number Line |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (5 ratings) — better |
| Positive reviews | 0.0% of reviews | 100.0% of reviews — better |
| Number of ratings | — | 5 — better |
| Update frequency | Every 3 weeks — better | Every 15 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 8.1 — better | 13.0 |
| Further details — not scored | ||
| Size | 416 MB | 16 MB |
| Age rating | 4+ | 4+ |
| Developer | DLR German Aerospace Center e.V. | Blastoff Design |
Customer experience
DLR COMETS
Number Line
In-app purchases
DLR COMETS
No in-app purchases
Number Line
No in-app purchases
Questions
Is DLR COMETS free?
Is Number Line free?
Do DLR COMETS or Number Line have ads?
Which is updated more often, DLR COMETS or Number Line?
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