Comparison

O vs Fluid Mechanics Calc

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

Head to head
About

O

This app provides a comprehensive offline tool for selecting standard rubber seal sizes, including O-Rings, X-Rings, and Back-Up Rings. It offers dimension searches, housing calculations for various sealing applications, and supports multiple international standards in both metric and imperial units.

Highlights
  • Offline standard rubber seal size selection
  • Search for O-Ring, X-Ring, and Back-Up Ring sizes
  • O-Ring housing calculations for sealing applications
  • Supports multiple international standards (AS568, METRIC, JIS, etc.)
  • Metric and Imperial unit support
  • Substitutable O-Ring size suggestions
Features
Read full description

GMORS O-Ring Master is the completed tool for standard rubber seal sizes. When you use this APP, you don't need to have internet and catalog. Except O-Ring sizes, it also includes the search functions of X-Ring and Back-Up Ring. Otherwise, you can also use O-Ring Housing to choose suitable O-Ring in your application. Main functions are as follows: Dimension Search:O-Ring, X-Ring and Back-Up Ring. - MM and Inch are both available. - Full standard O-Ring series: AS568, BS 4518, GB/T 3452.1, JIS B2401 P, JIS B2401 G, JIS B2401 S, JIS B2401 V, SMS 1586 and METRIC. - Collocated Back-Up for AS-568 O-Ring. - Substitutable O-Ring sizes within tolerance are available. O-Ring Housing: Piston Sealing、Rod Sealing and Face Sealing. - MM and Inch are both available. - Support calculation for both Static and Dynamic sealing applications (Face sealing is with static calculation only). - Up to 7 O-Ring standards ( AS568, METRIC, JIS B2401 P/G/S/V, JASO F404, GB/T 3452.1, BS 4518 and SMS 1586) for most of size requirement of different groove design.

About

Fluid Mechanics Calc

This utility app provides a comprehensive calculator for fluid mechanics, civil, and structural engineering parameters. It offers over 130 formulas and 360 calculation methods, supporting seamless unit system switching for analysis, design, and operation of fluid-related systems.

Highlights
  • 130+ fluid mechanics formulas
  • 360+ calculation methods
  • Unit system conversion (metric/US)
  • Favorite formula marking
  • High mathematical precision
  • Seamless unit switching
Features
Read full description

The app is useful for the fluid thinkers. This app covers a wide variety of topics and helps in analysis, design, maintenance and operation of fluid related systems. The calculator will provide results for different fluid mechanics, civil, structural, pipe flow and engineering parameters. It is useful in the fields of automotive, aviation, geology, space, biological applications, petroleum, marine systems and cylinder manufacturing. This app comes handy to students, engineers, analysts, researchers and the curious. Here are the useful features of this app LISTS 130+ FORMULAE Memorizing hundreds of formula is not the way to go when it comes to learning fluid mechanics 360+ METHODS OF CALCULATION This calculator allows a user to change subject of formula based on the variable he/she wants to calculate. The formula applied is displayed in the app CALCULATE FOR ANSWERS Key in the numbers, set units and see results. Switch upto three conversion units. The app accepts input and provides results to the highest mathematical precision MARK FAVORITES Easy markups for easy recall HOP SEAMLESSLY BETWEEN BETWEEN METRIC AND US (INCH) UNIT SYSTEMS The app maintains separate functioning of these unit systems. The app has a predefined library of units designated to each of them It would be a good idea to kill the app and re-open it once in a while with the internet. We constantly strive to update, increase and enrich the content of the app. Go fluid with this app in your pocket!

Screenshots

O4 screens
Fluid Mechanics Calc4 screens

Verdict

The call

The clearest difference is device support: Fluid Mechanics Calc at 3 against O's 1. Fluid Mechanics Calc also leads on ratings volume (3 vs 1). On price, rating, update cadence and ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for O against 5.0 for Fluid Mechanics Calc. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

UpkeepUpdate frequency

O ships an update every 11 months, Fluid Mechanics Calc every 22 months. The most recent releases landed on September 22, 2026 and September 19, 2026 respectively.

Scorecard2 real differences · 7 level
O versus Fluid Mechanics Calc: the parameters behind the verdict, then further details
ParameterOFluid Mechanics Calc
PriceFreeFree
Rating5.0 (1 ratings)5.0 (3 ratings)
Number of ratings13 — better
Update frequencyEvery 11 months — betterEvery 22 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS16.015.6 — better
Further details — not scored
Size47 MB108 MB
Age rating4+4+
DeveloperGE MAO RUBBER INDUSTRIAL CO., LTD.Trelleborg Sealing Solutions

Customer experience

O

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Fluid Mechanics Calc

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

O

No in-app purchases

None

Fluid Mechanics Calc

No in-app purchases

Questions

Is O free?
O is free to download, with no in-app purchases.
Is Fluid Mechanics Calc free?
Fluid Mechanics Calc is free to download, with no in-app purchases.
Which has better reviews, O or Fluid Mechanics Calc?
O and Fluid Mechanics Calc are both rated 5.0 out of 5 on the App Store, from 1 and 3 ratings respectively.
Do O or Fluid Mechanics Calc have ads?
Neither O nor Fluid Mechanics Calc shows ads.
Which is updated more often, O or Fluid Mechanics Calc?
O ships an update every 11 months, and Fluid Mechanics Calc every 22 months. Most recently, O was updated on September 22, 2026 and Fluid Mechanics Calc on September 19, 2026.

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