Knuckle vs True Ring Size
Price, ratings, monetisation and update history for both apps, side by side β with what reviewers say about each.
Knuckle
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Knuckle turns your screen into a ring sizer. Lay a ring you already own flat on the display, match the gold circle to the inside of the band, and read the size. That is the whole thing. No camera, no printing, no paper strips to cut out, no trip to a jeweler. Before the first measurement you line a bank or ID card up against an outline, once, so Knuckle learns exactly how large a millimetre is on your particular screen. Every reading after that is true to your device. You get the inner diameter in millimetres next to the sizes people actually ask for - US, UK, EU, Japan, Australia, Hong Kong and Italy. Each result carries an honest confidence band instead of one number pretending to be certain. Sizes are worth keeping. Save one under the person it belongs to, note the finger and the hand, and look it up later while you are standing in the shop. Send a clean size card to whoever is buying. Nothing leaves your device. No account, no sign in, and it all works with the network switched off. Privacy Policy: https://docs.google.com/document/d/e/2PACX-1vTDX9pxPOlUJl_skVUHPi99mAw0y2B2BYd_v1mJkoF3xW3rlOcW5KlYd4t93MMbbGhctSTnBTy7d_l6/pub Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
True Ring Size
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Find your ring size in seconds β no physical sizer needed. True Ring Size turns your phone into an accurate ring sizer that works fully offline. Two ways to measure: β’ Ring on screen β place a ring you already own on the display and resize the circle until it matches. β’ Finger on screen β line up the guides to your finger and read the size instantly. Calibrate once with any bank card for real-millimeter accuracy, then convert between US, UK, EU, Japan, China and Russia sizing β by diameter or circumference, in mm or inches. Why True Ring Size: β’ 100% offline β no internet permission, nothing leaves your phone β’ Free forever β no subscription, no in-app purchases β’ No ads, ever β’ No account, no tracking, no data collection β’ Save sizes for the whole family β perfect for surprise gifts and engagement rings β’ Full conversion chart for every country system Whether you are buying an engagement ring, a wedding band, or a gift, True Ring Size helps you order the right size online with confidence. Note: on-screen measuring depends on your screen; calibrate with a card and measure twice for best results.
Screenshots
Verdict
The clearest difference is in-app purchases: True Ring Size at none against Knuckle's 1. True Ring Size also leads on iOS requirement (13.0 vs 26.0). On price, ads and device support there is nothing between them.
Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS
Both are free to download. Knuckle sells 1 one-off in-app purchase. True Ring Size asks for nothing beyond the download.
| Parameter | Knuckle | True Ring Size |
|---|---|---|
| Price | Free | Free |
| Ads | No | No |
| In-app purchases | Yes | No β better |
| Devices | iPhone, iPad | iPhone, iPod |
| Requires iOS | 26.0 | 13.0 β better |
| Further details β not scored | ||
| Size | 12 MB | 31 MB |
| Age rating | 4+ | 4+ |
| Developer | Andrii Bashta | lapnito.cz s.r.o. |
In-app purchases
Knuckle
- Knuckle Lifetime$9.99
True Ring Size
No in-app purchases





