Comparison

HydroCalc Plus vs PDFSignerScanner

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

Head to head
About

HydroCalc Plus

A professional tool for hydraulic engineers to calculate pressure losses in piping systems. It supports US and SI units, offers an extensive pipe material and fittings database, and includes inverse calculations for design optimization.

Highlights
  • Friction head loss calculation (Hazen-Williams)
  • US and SI unit support
  • Extensive pipe material library
  • Fittings and valves database
  • Inverse calculation mode
  • Real-time results (velocity, losses)
Features
Read full description

The COMPLETE version of HydroCalc, with what the free app doesn't have: the FITTINGS SELECTOR. Pick elbows, valves, tees and reducers piece by piece and the app computes minor losses for you — in the calculator, the inverse calculator and the system curve. No K-value tables, no transcription errors. ALL INCLUDED: pump power, system curve, pipe database and Darcy-Weisbach with real fluids come with the app. One purchase, no in-app purchases. Professional hydraulic engineering tool for calculating pressure losses in piping systems. Essential for engineers, plumbers, and contractors designing water distribution networks. Key Features: Calculate friction head losses using industry-standard Hazen-Williams equation Support for both US (ft, gpm, psi) and SI (m, lps, bar) units Extensive pipe material library with pre-defined roughness coefficients (C-factors) Complete fittings and valves database including elbows, tees, valves, contractions, and expansions Inverse calculations to determine optimal pipe diameter, flow rate, or length for target head loss Real-time results showing velocity, friction loss, minor losses, and total system head loss What Sets Plus Apart: Unlike basic calculators, HydroCalc Plus accounts for both major losses (pipe friction) and minor losses (fittings and valves). The app includes a comprehensive database of K-factors for various components, allowing accurate total system pressure loss calculations. Perfect For: Water supply system design Irrigation network planning HVAC piping calculations Fire protection systems Industrial fluid transport Educational purposes in hydraulic engineering Technical Capabilities: The app considers all critical factors affecting pressure loss: flow velocity, pipe diameter, internal roughness, pipe length, and fitting configurations. Materials include PVC, polyethylene, steel, cast iron, concrete, and more with accurate C-factors ranging from 120-150. Inverse Calculation Mode: Unique feature allowing backward calculations - determine required pipe size for allowable head loss, maximum flow capacity, or optimal pipe length for your system constraints. Simple, intuitive interface with instant results. No internet connection required. Professional-grade calculations in your pocket. Note: the advanced modules are available in English and Spanish.

About

PDFSignerScanner

Easily add your signature to PDF documents. Create a signature by drawing, taking a photo, or importing an image. The app allows you to customize placement, size, and ink color before exporting a final, shareable PDF.

Highlights
  • Signature creation (draw, photo, import)
  • Signature background cleaning
  • Signature cropping
  • Customizable signature placement
  • Multiple ink colors
  • Export signed PDFs
Features
Read full description

Create your signature by drawing, photographing it on paper, or importing from Photos. The app cleans the background, lets you crop tightly around your signature, then place it anywhere on the PDF. Drag, resize, and choose from multiple ink colors before exporting a flattened, share-ready signed PDF.

Screenshots

HydroCalc Plus4 screens
PDFSignerScanner4 screens

Verdict

The call

The clearest difference is price: PDFSignerScanner at Free against HydroCalc Plus's $6.99. On review sentiment, update cadence, ads and in-app purchases 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

PDFSignerScanner is free to download; HydroCalc Plus costs $6.99 up front. HydroCalc Plus sells 4 one-off in-app purchases and PDFSignerScanner sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

HydroCalc Plus ships an update every 3 weeks, PDFSignerScanner every 11 days. The most recent releases landed on October 23, 2026 and October 6, 2026 respectively.

Scorecard2 real differences · 8 level
HydroCalc Plus versus PDFSignerScanner: the parameters behind the verdict, then further details
ParameterHydroCalc PlusPDFSignerScanner
Price$6.99Free — better
Rating5.0 (1 ratings) — better—
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings1 — better—
Update frequencyEvery 3 weeksEvery 11 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better16.0
Further details — not scored
Size34 MB13 MB
Age rating4+4+
DeveloperTransparent Blue Water LLCMANJUR KOLHAR

Customer experience

HydroCalc Plus

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

PDFSignerScanner

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

4 purchases

HydroCalc Plus

One-time4
  • Pump Power Calculator$1.99
  • System Curve Generator$1.99
  • Pipe Database$1.99
Show 1 more
  • Industrial Fluids Pack$2.99
1 purchases

PDFSignerScanner

One-time1
  • Lifetime Unlock$4.99

Questions

Is HydroCalc Plus free?
HydroCalc Plus costs $6.99, and also offers in-app purchases.
Is PDFSignerScanner free?
PDFSignerScanner is free to download, with in-app purchases available.
Do HydroCalc Plus or PDFSignerScanner have ads?
Neither HydroCalc Plus nor PDFSignerScanner shows ads.
Which is updated more often, HydroCalc Plus or PDFSignerScanner?
HydroCalc Plus ships an update every 3 weeks, and PDFSignerScanner every 11 days. Most recently, HydroCalc Plus was updated on October 23, 2026 and PDFSignerScanner on October 6, 2026.

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