# DLR COMETS vs Number Line

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.

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.

## The numbers

| Metric | DLR COMETS | Number Line |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (5 ratings)](https://appshunter.io/ios/app/number-line/id1531893217/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 15 months |
| Monetization | Free | Free |
| Size | 416 MB | 16 MB |
| Requires iOS | **8.1** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [DLR German Aerospace Center e.V.](https://appshunter.io/developer/418202933) | [Blastoff Design](https://appshunter.io/developer/1455360972) |

## What reviewers say

### DLR COMETS

[App page](https://appshunter.io/ios/app/dlr-comets/id1363156480)

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.

**Highlights:** Interactive comet model, Mission highlights and photographs, Historical background on comets, Rosetta mission science, Philae lander touchdown details, Personal stories from the mission

**Features:** macOS Compatibility

**In-app purchases:** none


### Number Line

[App page](https://appshunter.io/ios/app/number-line/id1531893217)

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.

**Highlights:** 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

**In-app purchases:** none


## Frequently asked questions

### Is DLR COMETS free?

DLR COMETS is free to download, with no in-app purchases.

### Is Number Line free?

Number Line is free to download, with no in-app purchases.

### Do DLR COMETS or Number Line have ads?

Neither DLR COMETS nor Number Line shows ads.

### Which is updated more often, DLR COMETS or Number Line?

DLR COMETS ships an update every 3 weeks, and Number Line every 15 months. Most recently, DLR COMETS was updated on November 2, 2026 and Number Line on November 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*