Comparison

Knuckle vs True Ring Size

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

Head to head
About

Knuckle

Features
Read full description

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/

About

True Ring Size

Features
Read full description

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

Knuckle4 screens
True Ring Size4 screens

Verdict

The call

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

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

Both are free to download. Knuckle sells 1 one-off in-app purchase. True Ring Size asks for nothing beyond the download.

Scorecard2 real differences Β· 3 level
Knuckle versus True Ring Size: the parameters behind the verdict, then further details
ParameterKnuckleTrue Ring Size
PriceFreeFree
AdsNoNo
In-app purchasesYesNo β€” better
DevicesiPhone, iPadiPhone, iPod
Requires iOS26.013.0 β€” better
Further details β€” not scored
Size12 MB31 MB
Age rating4+4+
DeveloperAndrii Bashtalapnito.cz s.r.o.

In-app purchases

1 purchases

Knuckle

One-time1
  • Knuckle Lifetime$9.99
None

True Ring Size

No in-app purchases

Questions

Is Knuckle free?
Knuckle is free to download, with in-app purchases available.
Is True Ring Size free?
True Ring Size is free to download, with no in-app purchases.
Do Knuckle or True Ring Size have ads?
Neither Knuckle nor True Ring Size shows ads.

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