iDrawlix Mobile vs Catalopedia
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iDrawlix Mobile
This app allows users to design and verify partially full conduits and open channels. It offers various cross-section types and hydraulic calculation models, displaying real-time flow depth and discharge. Users can also generate stage-discharge curves and analyze hydraulic grade lines.
- Playground concept for real-time experimentation
- Seven cross-section types
- Four hydraulic calculation models
- International and Imperial unit systems
- Real-time normal flow depth and discharge display
- Stage-Discharge curve generation
- Hydraulic Grade Line (HGL) representation
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iDrawlix® Mobile comes as free App, with two In App Purchases options which will unlock Watermarks and file sharing, respectively. It replaces iDrawlix® Premium, for which we will do not grant our assistance starting June, 30 2021, because his not full compatibility with iOS 13 or newer. It has been, fully recompiled in native Swift also for Mac OS. Now it is newer, faster and graphically more beautiful. iDrawlix® can handle a single Sewer or Open Channel, basing on the Playground concept. The iDrawlix® Playground concept allows Users approaching design and verification of partially full conduits or open channels to immediately experiment what happens to their project at any change in the settings, without the burden of building complex ad hoc models in order to get graphics and tables out of it. We chosen to provide iDrawlix® Mobile with the "Top Seven" types of cross section: - Open Channels: -Simple Trapezoidal; - Closed Channels/Sewers: -Rectangular, -Rectangular with Triangular Bottom, -Circular, -Egg-Shaped (old England Style), -Standard Egg-Shaped, -Elliptical. User can select four different Hydraulics Calculation Models: - Gauckler & Strickler, - Chezy-Bazin, - Chezy-Kutter and - Manning. Two different options of System Unit are available: - International System (IS) or - Imperial Units (IU). Each Cross Section, furthermore, can be characterised by two Roughness Coefficients: one for the bottom and one the edges (sides). All the necessary geometric parameters, are anyway explained graphically by the legend and the quotes next to the cross section represented within the Activity. iDrawlix® Mobile displays in real time, at any parameter change: - Normal Flow Depth and - Normal Flow Discharge. One of the main output of iDrawlix® Mobile is the Stage-Discharge curve of the current Cross Section. Each Parameter is plotted in the classic dimensionless scale vs. the ratio Yn/H, where: - Yn is the normal depth; - H is the maximum internal depth of the given Cross Section. In the bottom View, are tabled the following parameters, for each Y, assumed as normal depth Yn: - σn, as the Hydraulic Cross Section involved (m²) or (ft²), - HRn, as the Hydraulic Radius (m) or (ft), - χn, as the corresponding Wet Perimeter (m) or (ft), - Qn, as the normal Discharge (m³/s) or (ft³/s), - Vn, as the normal Velocity (m/s) or (ft/s), - Vc, velocity in critical conditions (m/s) or (ft/s), - Fr, that is the Froud number (n). iDrawlix® Mobile can represent also the HGL (Hydraulic Grade Line) for a given free surface channel or sewer, which is plotted under hypothesis of gradually varied flow. Users can consider Channels or Sewers of semidefinite length in the Mild Slope as well as in the Steep Slope case. Boundary conditions are set interactively by the User, imposing the known depth into the starting downstream cross section (profiles known as M1 and M2) for Mild Slope Channels or, in the opposite case, by imposing the known depth into the starting upstream cross section (profiles known as S2 and S3) for Steep Slope Channels. All the parameters computed within the integration used in order to plot the HGL graph, are represented also in the tabular format as follows: - Y(i) depth of the current. Dimensions: (m) or (ft); - X(i) abscissa corresponding to Y(i), computed as negative for upstream wise case (mild slope) and positive for downstream wise integrations (steep slope). Dimensions: (m) or (ft); - V(i) velocity of the current in the cross section i. Dimensions: (m/s) or (ft/s); - J(i) energy loss or gain between the i-th and the i+1-th cross section. Dimensions: (m/m) or (ft/ft); - E(i) energy computed as sum of the hydraulic grade and velocity head. Dimensions: (m) or (ft). We strongly recommend to buy the "Full unlock forever" In App Purchase in order to get the max from your iDrawlix® Mobile experience. Old Premium version owners are kindly requested to email to idrawlix@idrawlix.com in order to get a new free license.
Catalopedia
This app serves as a comprehensive encyclopedia for catalytic converters, offering free, unlimited searches. It provides transparent pricing, accurate metal and FX updates, and detailed 3D rendered images with exact measurements. The app also features an AI-powered identification tool and welcomes collaboration for expanding its product catalog.
- Unlimited free catalytic converter searches
- Transparent pricing with customizable rates
- Hourly updated metal and FX prices
- 3D rendered images with exact measurements
- AI-powered converter identification (Beta)
- Country-specific product differentiation
- Collaborative expansion of product catalog
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Transparent, Convenient, Collaborative Catalytic Converter Recycling App. Catalopedia is a catalytic converter encyclopedia with unlimited free searches to find the exact converter you are looking for. We offer a transparent pricing system, where you can choose your own return rates and other settings and customise the app to your personal requirements. We provide very accurate catalytic converter prices, our metals and FX prices are updated hourly. Our images are 3D rendered and all pictures are digital with exact measurements. Our sampling and analysis systems are refined, with processes to eliminate machine, human error and we do 6 analyses at minimum based on tolerance and deviation criterias to determine the final analysis before publishing on the app. Therefore, the analysis which can be purchased is extremely highly reliable. We differentiate the products by country, as you will realise converters with identical markings have differing analyses, therefore different prices, if they originate from different countries, due to their emission standards. We also have other means to filter the converters to dwindle down the searches. Test our Beta Identify feature. We render several thousand images of different backgrounds, simulating rust, dents etc from our 3D images. Then we feed them to our own AI neural network engine. This engine is able to learn and guess what you are looking for by shortlisting it. It however only works for models in our catalogue and we are training it every day, as we add products. So in the testing phase, it's completely free. We have a highly collaborative mindset. We have a good application, but our products are very limited to a few countries. If your country’s products are not covered in the application, we would be happy to discuss with you and obtain samples to include them in the app. We are also looking for franchise partners who want to be part of our application. We are more than happy to collaborate and share the benefits.
Screenshots
Verdict
iDrawlix Mobile and Catalopedia both sit at 1.0 stars, but that hides the real split: 100% of iDrawlix Mobile's written reviews are positive against 0% of Catalopedia's. Catalopedia's advantage is update cadence (every 3 weeks vs every 10 months) and iOS requirement (13.0 vs 17.2). On price, rating, ratings volume 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
Both are free to download. iDrawlix Mobile sells 2 one-off in-app purchases and Catalopedia sells 5 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 1.0 for iDrawlix Mobile against 1.0 for Catalopedia. Both are backed by a comparable volume of ratings — 1 and 2 respectively. Written reviews are what separate them: 100% of iDrawlix Mobile's written reviews are positive against 0% of Catalopedia's.
iDrawlix Mobile ships an update every 10 months, Catalopedia every 3 weeks. The most recent releases landed on September 29, 2026 and October 15, 2026 respectively.
| Parameter | iDrawlix Mobile | Catalopedia |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) | 1.0 (2 ratings) |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 1 | 2 — better |
| Update frequency | Every 10 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, Mac — better | iPhone, iPod |
| Requires iOS | 17.2 | 13.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 61 MB |
| Age rating | 4+ | 4+ |
| Developer | Studio Envisys | Skrya Pte Ltd |
Customer experience
iDrawlix Mobile
Catalopedia
In-app purchases
iDrawlix Mobile
- Watermarks unlock forever.$2.99
- Full unlock forever.$5.99
Catalopedia
- 30 Credits$29.99
- 66 Credits$59.99
- 144 Credits$99.99
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- 225 Credits$179.99
- 360 Credits$229.99
Questions
Is iDrawlix Mobile free?
Is Catalopedia free?
Which has better reviews, iDrawlix Mobile or Catalopedia?
Do iDrawlix Mobile or Catalopedia have ads?
Which is updated more often, iDrawlix Mobile or Catalopedia?
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