HydroSewer vs Unit Converter Engineering Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HydroSewer
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HydroSewer is a professional stormwater and sewer network analysis tool powered by the EPA SWMM 5 engine. Build, analyze, and simulate drainage networks from your phone or tablet. KEY FEATURES - Import standard EPA SWMM input files (.inp) and simulate them with the EPA SWMM 5 engine on your device, with no account and no cloud - Junctions, outfalls, storage, conduits, pumps, weirs, orifices, and subcatchments on an interactive canvas - Step through results over time: depth at nodes, flow and velocity in conduits, and more - Edit node, link, and subcatchment properties; renaming or deleting an element updates the data that refers to it, and broken references in older projects can be repaired - Give a node its sewage flow (DWF), with an optional hourly pattern, and a direct inflow; before a run, the app flags flat pipes, unset manholes, or no inflow at all - New network, Save, and Save as in the menu; Demo Village, a sample network, to try it all MAP BACKGROUND (OPTIONAL) - Your network over Google Maps, map or satellite, with adjustable visibility - Find your area on the map: tap your town and HydroSewer proposes the coordinate system that fits, if it knows one - Or set UTM, or a Transverse Mercator grid in Advanced - A .inp that declares a supported EPSG code (Q_VAR_PROJECTION) lands in place with no setup - Local coordinates? Line the network up by tapping a node and its place on the map, a few times - You turn the map on. It needs a connection; without one, the network is shown without it LAY OUT A NETWORK IN THE FIELD Start a new network and tap Use my location: the map centers where you are and a dot shows your position as you walk. Add each manhole by tapping its place on the map; your location never places or moves one. A preliminary layout, not a survey. FIELD NOTES - Attach notes and photos to any manhole, outfall, or pipe: as-built discrepancies, observations, a "check this" for the office - Open or resolved; elements with open notes are highlighted, and one list gathers every open note - With location allowed, a note records where it was taken and how accurately, with Show on map - Saved in your project, never in the .inp file CORE FEATURES WITHOUT INTERNET Modeling, simulation, saving, and field notes work with no connection, wherever the signal doesn't reach. Apart from the store's purchase service, only the optional map background uses the internet, through Google Maps. PRIVACY Transparent Blue Water does not receive your data. When you turn on the optional map background, Google Maps receives the map area you view. Your GPS reading, if you allow it, is used on your device and never sent anywhere; a note's position stays in your project and its PDF until you share them. FREE, WITH NO SIZE CAP No cap on network size, field notes, or photos; the map background is free too. HydroSewer Pro is an optional one-time purchase that adds: - Export the network as a standard SWMM .inp file - Export node and link results to CSV, every time step - A PDF report of your field notes with your logo, model data per element, the photos, and map links to where notes were taken - Save a network's alignment on the map IMPORTANT HydroSewer is an independent engineering tool. Results are computed by the EPA SWMM 5 engine and must be reviewed and verified by a qualified, responsible engineer before any design, construction, permitting, or other professional use. HydroSewer does not certify or guarantee compliance with any code, standard, or regulation, and is provided "AS IS" without warranty of any kind. HydroSewer is not affiliated with, endorsed by, or sponsored by the U.S. Environmental Protection Agency (EPA). References to EPA and SWMM are used solely to identify the simulation engine. Map data and imagery: Google Maps.
Unit Converter Engineering Pro
This app provides precise unit conversions for engineers, scientists, and students. It supports over 100 units across 35 categories, including scientific notation and 9-digit decimal precision. The tool works offline and adheres to SI, NIST, and ISO standards.
- Over 100 units in 35+ categories
- Scientific notation support
- 9-digit decimal precision
- SI, NIST, ISO compliant
- Offline functionality
- Specialized units included
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Unit Converter Engineering Pro – The ultimate tool for engineers, scientists, and students who need precise and fast unit conversions. Easily convert between over 100 units across more than 35 categories commonly used in engineering, physics, chemistry, and mathematics. Perfect for professionals, researchers, and students who want a reliable, professional-grade converter at their fingertips. Included categories: • Acceleration • Angle • Area • Specific Heat • Electric Charge • Heat Transfer Coefficient • Length • Concentration • Thermal Conductivity • Physical Constants • Density • Diffusivity • Energy • Heat Flux • Force • Illuminance • Luminance • Mass • Moment / Torque • Power • ppm / ppb / ppt / % • SI Prefix • Pressure • Radiation – Activity • Radiation – Dose • Radiation – Exposure • Radiation – Equivalent Dose • Time • Volume • Velocity / Speed • Viscosity • Volume Flow Rate • Voltage / Electric Potential • Frequency • Temperature Key Features: • Supports scientific notation for extreme precision • Fully compliant with SI, NIST, and ISO standards • 9-digit decimal precision for engineering-grade accuracy • Fast and intuitive interface • Works offline – no internet required • Includes rare and specialized units often missing from other converters • Made by engineers, for engineers Simplify your work, save time, and ensure accuracy with Unit Converter Engineering Pro - your professional unit conversion companion. EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is update cadence: Unit Converter Engineering Pro at weekly against HydroSewer's every 3 weeks. Unit Converter Engineering Pro also leads on iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases 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. HydroSewer sells 1 one-off in-app purchase and Unit Converter Engineering Pro sells 2 in-app purchases, starting at $5.99 per 7 days. Whichever you choose, the download price is not the number that matters.
HydroSewer ships an update every 3 weeks, Unit Converter Engineering Pro weekly. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.
| Parameter | HydroSewer | Unit Converter Engineering Pro |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (3 ratings) — better |
| Number of ratings | — | 3 — better |
| Update frequency | Every 3 weeks | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 51 MB | 77 MB |
| Age rating | 4+ | 4+ |
| Developer | Transparent Blue Water LLC | Kaiguri Tech |
In-app purchases
HydroSewer
- HydroSewer Pro$14.99
Unit Converter Engineering Pro
- 3-Day Trial3 Days trial$5.997 Days
- Yearly Plan$19.991 Year
Questions
Is HydroSewer free?
Is Unit Converter Engineering Pro free?
Do HydroSewer or Unit Converter Engineering Pro have ads?
Which is updated more often, HydroSewer or Unit Converter Engineering Pro?
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