Comparison

Chemical Engineering Formulate vs rubyi

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

Head to head
About

Chemical Engineering Formulate

This comprehensive reference tool provides over 1,500 formulas, calculators, and conversion charts for chemical engineering professionals and students. It covers a wide range of topics including heat transfer, fluid mechanics, and reaction kinetics, with support for both US and Metric units.

Highlights
  • 1,500+ formulas and calculators
  • 700+ engineering calculators
  • US/Metric unit toggle
  • Dual-unit display
  • Searchable reference tables
  • Offline functionality
  • Save and share calculations
Features
Read full description

CHEMICAL ENGINEER is the essential tool for Chemical Engineers, Process Engineers, and engineering students. With over 1,500 formulas and calculators, this is the most comprehensive chemical engineering reference app available. The app features 700+ engineering calculators across 50 categories, 750 conversion formulas, 8 temperature scales, and 14 reference tables. All formulas support US and Metric (SI) units with one-tap toggle and dual-unit display. CORE CHEMICAL ENGINEERING - Heat Transfer -- LMTD, overall heat transfer, fin efficiency, radiation, Fourier's law - Fluid Mechanics -- Reynolds number, Bernoulli, Darcy-Weisbach, Hagen-Poiseuille - Thermodynamics -- Ideal gas, Clausius-Clapeyron, Antoine equation, compressibility - Reaction Kinetics -- Arrhenius equation, rate laws, CSTR/PFR design, Levenspiel - Mass Transfer -- Fick's law, mass transfer coefficients, wetted wall columns - Distillation -- McCabe-Thiele, Fenske, Underwood, relative volatility - Dimensionless Numbers -- Reynolds, Nusselt, Prandtl, Schmidt, Sherwood, Grashof UNIT OPERATIONS Filtration, Packed/Fluidized Beds, Compressor Sizing, Mixing, Cooling Towers, Membrane Separation, Crystallization, Liquid-Liquid Extraction, Adsorption PROCESS & SAFETY Process Economics, Process Control, Safety Engineering, Corrosion and Electrochemistry ENVIRONMENTAL Air Quality, River/Lake/Soil Pollution, Infiltration and Recharge, Evaporation, Waste ADDITIONAL CATEGORIES Piping (70), Pressure Stress (109), Material Weight (101), Area Formulas (60), Flat Plates, Pumps, Pump Laws, Steam, Crusher, Vapor Separators, Equilibrium, Cogeneration, and more CONVERSIONS BTU, Cubic, Flows, Ft-Lbs, Horsepower, HVAC, Hydraulic, Linear, Liquid, Metric (460), Power, Pressures, Square Measures, Watts, Weights TEMPERATURE SCALES Celsius, Fahrenheit, Kelvin, Rankine, Reaumur, Newton, Delisle, Romer 14 REFERENCE TABLES Chemical Properties, Steam Tables, Pipe Schedules, Material Densities, pH Scale, Engineering Constants, Chemical Resistance, Water Quality, Critical Properties, Antoine Constants, Heat Transfer Coefficients, Dimensionless Numbers, Gas Properties, Flammability Limits FEATURES - US/Metric toggle with dual-unit display - Save calculations and favorites - Share and export results - Searchable reference tables - Dark mode interface - Works offline Don't see a formula you need? Email us and we'll include it in the next update.

About

rubyi

Learn, run, and share Ruby scripts with an iOS app offering code completion, syntax highlighting, and a built-in browser. Customize your coding environment and even run code on your Apple Watch.

Highlights
  • Autocomplete
  • Auto Indent
  • Code coloring
  • Run selected text
  • Apple Watch code execution
  • Code templates
  • File system support
Features
Read full description

This is an ios ruby app,you can learn,run,share ruby script. Features : Autocomplate. Auto Indent. Code color. In(the built-in browser or the txt editor),Select the text to run. Horizontal screen development. Code templates,the contents of the new file is copy from contents of the template file. *You can run code on the Apple Watch! *You can enter ruby code by keyboard, and then you can execut the ruby code,support the gets function. *You can use the file system to supports txt, pdf, chm, mp3,m4v,zip, gif, png, html, rb ,doc... *You can adjust the code color and font size , and support to move the cursor left and right and up and down , easy to read and write. *You can find learning materials by the built-in browser . *You can save ruby code and learning materials, and can be modified to the save file and delete the save file . *You can control the background image and color, and execution voice , background animation, text color and shadow, switch interface animation , the number and the order of the main interface of the tab bar to create your learning software. *You can Learn ruby knowledge , the system provides some basic learning materials . *You can use ruby code or learning materials to generate two-dimensional code , for easy sharing . *You can share code by Email,Weibo,Twitter,Facebook. *You can use the counter,light in the Setting tab.

Screenshots

Chemical Engineering Formulate4 screens
rubyi4 screens

Verdict

The call

The clearest difference is review sentiment: rubyi at 82% against Chemical Engineering Formulate's 0%. rubyi also leads on price (Free vs $4.99) and update cadence (every 3 months vs every 8 months). On 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

rubyi is free to download; Chemical Engineering Formulate costs $4.99 up front. Chemical Engineering Formulate sells 1 one-off in-app purchase and rubyi sells 7 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Chemical Engineering Formulate ships an update every 8 months, rubyi every 3 months. Both last shipped on October 23, 2026.

Scorecard6 real differences · 4 level
Chemical Engineering Formulate versus rubyi: the parameters behind the verdict, then further details
ParameterChemical Engineering Formulaterubyi
Price$4.99Free — better
Rating—4.7 (27 ratings) — better
Positive reviews0.0% of reviews81.7% of reviews — better
Number of ratings—27 — better
Update frequencyEvery 8 monthsEvery 3 months — better
AdsNoNo
In-app purchasesYesYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPadiPhone, iPad, iPod, Apple Watch — better
Requires iOS18.614.0 — better
Further details — not scored
Size19 MB45 MB
Age rating4+17+
DeveloperHistorycentral.com小文 黄

Customer experience

Chemical Engineering Formulate

Written reviews7 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

rubyi

All ratings27 ratings
Positive92.6%
Neutral3.7%
Negative3.7%
Written reviews153 reviews
Positive81.7%
Neutral3.9%
Negative14.4%

In-app purchases

1 purchases

Chemical Engineering Formulate

One-time1
  • Chemistry Pro$3.99
7 purchases

rubyi

One-time7
  • To remove ads$0.99
  • Password Service$0.99
  • Horizontal screen development$0.99
Show 4 more
  • Simple Vedio$0.99
  • Encryption Compression$0.99
  • Text Search$0.99
  • Autocomplete$0.99

Questions

Is Chemical Engineering Formulate free?
Chemical Engineering Formulate costs $4.99, and also offers in-app purchases.
Is rubyi free?
rubyi is free to download, with in-app purchases available.
Do Chemical Engineering Formulate or rubyi have ads?
Neither Chemical Engineering Formulate nor rubyi shows ads.
Which is updated more often, Chemical Engineering Formulate or rubyi?
Chemical Engineering Formulate ships an update every 8 months, and rubyi every 3 months. Most recently, Chemical Engineering Formulate was updated on October 23, 2026 and rubyi on October 23, 2026.

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