CatalogueMessier vs Rock Identifier
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CatalogueMessier
Explore the Messier, NGC, and Caldwell astronomical catalogs. Log your observations with photos, filter celestial objects by type, and track your progress with detailed statistics. Export your data for further analysis.
- View Messier, NGC, and Caldwell catalogs
- Add observation photos
- Filter objects by category
- Track observation progress
- Export observation data
- Multi-language support
Read full descriptionHide full description
The application allows you to view the 110 objects in the Messier catalog, the 812 main objects in the New General Catalog (NGC), and the 109 objects in the Caldwell catalog. You can add photos taken during your observations for each object. You can filter objects by category (galaxies, nebulae, clusters) and view the observation order for the annual Messier Marathon. Statistics allow you to track the progress of your observations. Export your photos to a spreadsheet summarizing your observations. Statistics allow you to track the progress of your observations. Privacy: - No ads. - No data collection. - No registration (neither by email nor locally). - No tracking. - No location tracking. - No connection to a server to collect information. Languages: French, English, Italian, German, Dutch, Chinese, Japanese, Spanish, Portuguese, Dutch.
Rock Identifier
Read full descriptionHide full description
Point your camera at a rock or mineral and Rocco tells you what it is — then helps you confirm it with the same tests geologists actually use. Identify from multiple angles - Guided capture: the whole specimen, a close-up of the surface, and a fresh break or cut face - Rock class or mineral group, chemical formula, and crystal system - Hardness on the Mohs scale, luster, streak color, and common colors - Formation, common locations, and typical uses - Estimated value range and hazard notes where relevant Confirm it yourself with guided field tests - A step-by-step Mohs hardness test using a fingernail, a copper coin, glass, and steel - A guided streak test to read a mineral's true powder color - Identification tips specific to what you found Build a real collecting record - Mark find sites on a map so you remember exactly where each specimen came from - Save specimens to your collection or a wishlist, with a full scan history - Ask Rocco's AI companion follow-up questions about any rock or mineral Identification is based on visual AI analysis and may be inaccurate, especially for specimens that look similar but differ in composition. Hardness and streak tests can mark or damage a specimen — test on an inconspicuous spot, and skip testing anything you'd rather keep pristine. Terms of Use (EULA): https://drive.google.com/file/d/1tKMiMuHcAe4zS6HUwAiIvkX0l8ruLYzz/view?usp=sharing Privacy Policy: https://drive.google.com/file/d/1tKMiMuHcAe4zS6HUwAiIvkX0l8ruLYzz/view?usp=sharing
Screenshots
Verdict
The clearest difference is price: Rock Identifier at Free against CatalogueMessier's $0.99. Rock Identifier also leads on update cadence (every 8 days vs every 3 weeks). CatalogueMessier's advantage is in-app purchases (none vs 3). On 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
Rock Identifier is free to download; CatalogueMessier costs $0.99 up front. Rock Identifier sells 3 in-app purchases, starting at $4.99 per 7 days. CatalogueMessier asks for nothing beyond the download.
CatalogueMessier ships an update every 3 weeks, Rock Identifier every 8 days. The most recent releases landed on November 5, 2026 and November 11, 2026 respectively.
| Parameter | CatalogueMessier | Rock Identifier |
|---|---|---|
| Price | $0.99 | Free — better |
| Positive reviews | 0.0% of reviews | — |
| Update frequency | Every 3 weeks | Every 8 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | — |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 9 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Laurent DURLIAT | Ebubekir Sezer |
In-app purchases
CatalogueMessier
No in-app purchases
Rock Identifier
- Weekly$4.997 Days
- Monthly$9.991 Month
- Yearly3 Days trial$39.991 Year
Questions
Is CatalogueMessier free?
Is Rock Identifier free?
Do CatalogueMessier or Rock Identifier have ads?
Which is updated more often, CatalogueMessier or Rock Identifier?
Other comparisons















