100cm Ruler vs Ruler
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
100cm Ruler
This app provides a digital ruler for measuring the length and diameter of small objects directly on your device. It features a millimeter scale and allows for easy sliding to measure.
- Digital ruler functionality
- Millimeter scale
- Diameter measurement
- Screen sliding for measurement
- Ad removal option
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Plotting scale is useful to measure the length of small articles and insects. Squared in millimeters on the lower left, thus the diameter can be measured roughly. Hold the screen and slide your iPhone to the right. https://www.youtube.com/watch?v=kxU9xi88IiY Ads can be removed on "Info page".
Ruler
This application provides a precise measurement tool by rendering according to your device's screen width specifications. It has been tested on a wide range of Apple devices to ensure accuracy for your measuring needs.
- Accurate screen-based rendering
- Device-specific calibration
- Wide device compatibility
- Precise measurement tool
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You may already noticed that most of ruler apps are actually wrong. Accurate Ruler renders according to screen width spec of the device that your are currently using. So It is accurate. Already tested in following devices including: iPhone X, XR, XS, Max All sizes of iPad 2019 iPhone 4 iPhone 4s iPhone 5 iPhone 5s iPhone 5c iPhone 6 iPhone 6 plus iPhone 6s iPhone 6s plus iPhone se iPhone 7 iPhone 7 plus iPad 2 iPad 3 iPad 4 iPad air iPad air 2 iPad mini iPad min 2 iPad min 3 iPad mini 4 iPad pro, iPod Touch 5/6 If your device is one of them, we insure it is accurate.
Screenshots
Verdict
The clearest difference is rating: 100cm Ruler at 4.0 against Ruler's 2.6. 100cm Ruler also leads on iOS requirement (12.0 vs 15.6). Ruler's advantage is in-app purchases (none vs 1) and ratings volume (40 vs 1). On price, update cadence, ads 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. 100cm Ruler sells 1 one-off in-app purchase. Ruler asks for nothing beyond the download.
100cm Ruler holds the better App Store score, 4.0 against 2.6. That said, the two scores are not equally well evidenced: Ruler has 40 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 45% of 100cm Ruler's written reviews are positive against 54% of Ruler's, so the app with the better star average is not the one people write more warmly about.
100cm Ruler ships an update every 3 months, Ruler every 5 months. The most recent releases landed on June 11, 2026 and August 17, 2026 respectively.
| Parameter | 100cm Ruler | Ruler |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (1 ratings) — better | 2.6 (40 ratings) |
| Positive reviews | 45.1% of reviews | 54.2% of reviews — better |
| Number of ratings | 1 | 40 — better |
| Update frequency | Every 3 months — better | Every 5 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 12.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 62 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | ZOOMO, Inc. | 祥祎 刘 |
Customer experience
100cm Ruler
Ruler
Bugs and requests
100cm Ruler
Not enough reviews yet to summarise bugs or requests.
Ruler
Reported bugs
10 issues- White/blank screen display on newer iOS versions
- App crashes and freezes on launch
- Ruler not rendering or displaying
- Toggle switches stuck in grey/disabled state
- Incorrect device identification (iPad size misidentification)
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- Incompatibility with iOS 13.3 and newer
- Authenticator code clipboard access on launch
- Screen rotation issues
- Inaccurate ruler scaling on iPhone 8, 11, 12, 13, 16 Pro
- App requests rating before allowing use
Requested features
7 requests- Support for iPhone 12, 13, 14, 15, 16 and newer models
- Millimeter measurement option
- Longer ruler display
- Fractional inches (1/16, 1/8) instead of decimal inches
- Support for newer iPad models
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- Ability to disable ads
- Better device detection and compatibility
In-app purchases
100cm Ruler
- Remove ADS$1.99
Ruler
No in-app purchases
