Image Ruler vs CAPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Image Ruler
This app allows you to measure objects directly on photos. Simply take a picture, mark a known object for reference, and then draw measurements on other items within the same image. It supports both metric and imperial units and offers intuitive editing tools.
- Measure objects on photos
- Use a known object as a reference
- Supports metric and imperial units
- Intuitive editing interface
- Organize photos easily
- Zoom for precision
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Measure anything in any photo. Take a photo or import one from your library, place a reference object you already know the size of, and instantly calculate real-world measurements — lengths, angles, and areas — directly on the image. How it works Set a reference line on a known object in your photo. From there, every measurement you draw is automatically calculated in real scale. What you can measure Ruler — measure distances and lengths Arrow — annotate with directional measurements Angle — measure the angle between any two lines Area — tap points to outline a surface and calculate its area Built for precision Works entirely offline — no internet required Metric and imperial units Pinch to zoom for precise point placement Undo and redo any change Hide or show your reference line at any time Tips for accurate results For best accuracy, make sure your reference object and the object you're measuring are in the same plane, and that the camera was parallel to both when the photo was taken. Perspective distortion affects results. Measurements are estimates based on the reference you provide.
CAPN
This app connects users with trained community members for assistance in unsafe situations. It provides a network of trusted individuals ready to help when you feel vulnerable.
- Community-assisted protection
- Trained and trusted members
- Local assistance
- Safety network
- Compassionate support
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CAPN (Community Assisted Protection Network) is a mobile application that allows its users to summon a trained, trusted, and compassionate member of their local community to assist them in situations where they feel unsafe.
Screenshots
Verdict
The clearest difference is rating: CAPN at 5.0 against Image Ruler's 1.5. CAPN also leads on in-app purchases (none vs 7) and update cadence (every 2 days vs every 3 weeks). Image Ruler's advantage is ratings volume (44 vs 3). On price, ads, monetization model 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
Both are free to download. Image Ruler sells 5 one-off in-app purchases. CAPN asks for nothing beyond the download.
CAPN holds the better App Store score, 5.0 against 1.5. That said, the two scores are not equally well evidenced: Image Ruler has 44 ratings behind it against 3, so its average is the more settled of the two.
Image Ruler ships an update every 3 weeks, CAPN every 2 days. The most recent releases landed on October 4, 2026 and October 15, 2026 respectively.
| Parameter | Image Ruler | CAPN |
|---|---|---|
| Price | Free | Free |
| Rating | 1.5 (44 ratings) | 5.0 (3 ratings) — better |
| Positive reviews | 17.6% of reviews | — |
| Number of ratings | 44 — better | 3 |
| Update frequency | Every 3 weeks | Every 2 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.1 | 15.1 |
| Further details — not scored | ||
| Size | 47 MB | 47 MB |
| Age rating | 4+ | 4+ |
| Developer | Martin Schurmann | CAPN LLC |
Customer experience
Image Ruler
CAPN
In-app purchases
Image Ruler
- imageRulerPro$0.99
- Small Tip2 variants$0.99
- Medium Tip2 variants$2.99
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- Big Tip$4.99
- Big tip$4.99
CAPN
No in-app purchases









