Comparison

Rock Identifier vs Modern GB Stamp Decoder

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

Head to head
About

Rock Identifier

Identify rocks, minerals, and crystals instantly using your phone's camera. Get detailed scientific information, track your finds, and organize your collection with this user-friendly geology companion.

Highlights
  • AI-powered multi-angle identification
  • Instant rock, mineral, and crystal identification
  • Detailed scientific information
  • Collection manager
  • Location tracking for finds
  • Educational content
Read full description

Rock Identifier is your ultimate companion for understanding every detail and property about any rock, mineral, or crystal. Whether you're a geology enthusiast, collector, or simply curious about the earth's materials, our app provides comprehensive information at your fingertips. Key Features: Multi-Angle Identification: • Capture up to 4 photos from different angles for enhanced accuracy • Include close-ups of unique features and textures • Add context about where and how you found the specimen • Smart analysis considers multiple perspectives for precise identification Instant Identification: • Quickly identify rocks, minerals, diamonds, fossils, stones, and crystals • Get alternative possibilities with confidence ratings • Receive detailed explanations for each identification • AI-powered analysis for accurate results Detailed Information: • Scientific name and classification • Mineral composition • Hardness rating on the Mohs scale • Crystal system and structure • Formation process and geological origin • Common uses and applications • Associated minerals and environments User-Friendly Interface: • Navigate effortlessly through a clean and intuitive design • Simple guided capture process • Clear visual presentation of information • Easy-to-use collection management Additional Features: • Location Tracking: Record where you found your specimens • Collection Manager: Organize and catalog your personal rock collection • Educational Content: Learn about geological processes and rock formation • Interactive Chat: Ask questions about your identified specimens ----- Legal Notice ----- Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Modern GB Stamp Decoder

Features
Read full description

Scan Ā· Decode Ā· Collect. Modern GB Stamp Decoder helps you explore modern Great Britain barcoded stamps and keep a digital record of the items you own. Built for collectors of QEII and King Charles III stamps, it brings scanning, the Modern GB digital Catalogue and your own collection together. SCAN AND DECODE Scan a supported stamp's Data Matrix barcode with your camera, or paste the barcode text. No stamp to hand? Open the example decode to see how it works. Read the decoded information alongside matching catalogue details, including face value, colour, issue date, barcode generation date and security overlays where available. YOUR DIGITAL COLLECTION Save your own stamps, booklets and sheets in clearly separated sections. Record the condition and visible characteristics of your copies, with booklet details kept distinct from the stamps inside. Saved observations belong to your collection; they are not replaced by catalogue updates. CATALOGUE AND CHECKLIST Browse the Modern GB digital Catalogue using our own MGB references. Use the separate checklist to see what you have and need, organised by stamps, booklets and other collecting formats. Choose a simple checklist or separate Mint and Used boxes, and search or filter the catalogue to focus on your interests. GUIDED COLLECTOR CHECKS Compare security backing paper using a step-by-step visual guide. Open it from Scan or while recording an item. Use SBP or PB names in Settings, and choose 'I'm not sure' when a characteristic cannot be established. OPTIONAL PRO FEATURES Start with free stamp decoding and save up to 25 collection items. Five free Collector Checks let you try the guided identification tools. An optional Pro subscription adds unlimited collection saves and Collector Checks, enhanced catalogue detail, advanced decoding features, and Stamp card image and print tools. See the in-app purchase screen for prices and subscription terms. ON YOUR DEVICE No collection account is required. Decoding and collection storage work on your device. Use Back up to keep a separate copy of your saved collection. Cloud collection synchronisation is not included in this version. Decoding and catalogue matching provide collecting information, not proof that a stamp is genuine or valid for postage. Some details require you to examine the physical stamp, booklet or sheet. Some images used with permission of Royal Mail Ā© 2026. Not a Royal Mail product. Ā© 2026 Modern GB Stamps. Privacy policy: https://stampdecoder.app/privacy/ Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Rock Identifier4 screens
Modern GB Stamp Decoder4 screens

Verdict

The call

The clearest difference is update cadence: Modern GB Stamp Decoder at every 9 days against Rock Identifier's every 3 weeks. Modern GB Stamp Decoder also leads on iOS requirement (15.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

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

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

Both are free to download. Rock Identifier sells 7 in-app purchases, starting at $2.99 per 7 days and Modern GB Stamp Decoder sells 2 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Rock Identifier ships an update every 3 weeks, Modern GB Stamp Decoder every 9 days. The most recent releases landed on October 24, 2026 and October 23, 2026 respectively.

Scorecard2 real differences Ā· 6 level
Rock Identifier versus Modern GB Stamp Decoder: the parameters behind the verdict, then further details
ParameterRock IdentifierModern GB Stamp Decoder
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 3 weeksEvery 9 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFreemium—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.015.0 — better
Further details — not scored
Size27 MB96 MB
Age rating4+4+
DeveloperIdeas All Day Ltd.Modern GB

In-app purchases

7 purchases

Rock Identifier

Subscriptions7
  • Unlimited Access3 Days trial$2.997 Days
  • Unlimited Weekly3 Days trial$3.997 Days
  • Unlimited Access3 Days trial$4.997 Days
Show 4 more
  • Unlimited yearly$19.991 Year
  • Unlimited Yearly$24.991 Year
  • Unlimited Yearly$29.991 Year
  • Unlimited Yearly$34.991 Year
2 purchases

Modern GB Stamp Decoder

Subscriptions2
  • Pro Core Monthly$0.991 Month
  • Pro Core Annual3 Months trial$9.991 Year

Questions

Is Rock Identifier free?
Rock Identifier is free to download, with in-app purchases available.
Is Modern GB Stamp Decoder free?
Modern GB Stamp Decoder is free to download, with in-app purchases available.
Do Rock Identifier or Modern GB Stamp Decoder have ads?
Neither Rock Identifier nor Modern GB Stamp Decoder shows ads.
Which is updated more often, Rock Identifier or Modern GB Stamp Decoder?
Rock Identifier ships an update every 3 weeks, and Modern GB Stamp Decoder every 9 days. Most recently, Rock Identifier was updated on October 24, 2026 and Modern GB Stamp Decoder on October 23, 2026.

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