Comparison

ResToolbox3 vs PDF to ePUB

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

Head to head
About

ResToolbox3

This petroleum engineering calculator provides rapid answers for engineers in the field or office. It offers comprehensive tools for fluid properties, gas hydrate prediction, nodal analysis, production forecasting, volumetrics, and well testing, all accessible offline.

Highlights
  • Fluid properties (PVT) analysis
  • Gas hydrate prediction
  • Nodal analysis for wells
  • Production forecasting
  • Volumetric calculations
  • Well test analysis
  • Offline functionality
Features
Read full description

ResToolbox3 is a petroleum engineering calculator built for engineers who need answers fast - on a rig floor, in a meeting, or on a plane. PVT analysis, nodal analysis, gas hydrate prediction, production forecasting, volumetric calculations, and well testing, all from your iPhone or iPad. FLUID PROPERTIES (PVT) - Gas PVT: Z-factor, viscosity, compressibility, pseudo-pressure, water content, and thermal properties via 5-component Peng-Robinson EOS. Handles CO2, H2S, N2, H2, and hydrocarbon mixtures including pure and high-concentration cases - Oil PVT: Bubble point, solution GOR, formation volume factor, viscosity, and compressibility using Valko-McCain and Velarde correlations. Three solve modes with scaling factors for GOR and viscosity - Brine & Rock: Soreide-Whitson mutual solubility with Spivey brine correlations. Gas composition from Gas PVT flows through automatically GAS HYDRATES - Hydrate formation prediction via Motiee and Towler-Mokhatab correlations - Thermodynamic inhibitor dosing for MEG, DEG, TEG, methanol, and ethanol - Interactive P-T stability curves with inhibited and uninhibited envelopes - Water content mass balance between reservoir and operating conditions NODAL ANALYSIS - Gas and oil well inflow performance (IPR) with non-Darcy flow and Vogel - Outflow performance (VLP) via four methods: Woldesemayat-Ghajar, Hagedorn-Brown, Beggs & Brill, and Gray - 3x3 sensitivity matrix or real-time Explorer mode with interactive sliders - Water cut modelling with physics-based two-phase flow - Injection well support PRODUCTION FORECASTING - Single-well decline profiles: hyperbolic, exponential, and harmonic - Two-stage decline with continuous slope matching - Multi-well field development with drilling schedule, plateau constraints, and abandonment rate VOLUMETRICS - Deterministic OGIP and OOIP with combined gas/oil mode - Monte Carlo probabilistic analysis with Normal, Log-Normal, and Triangular distributions - Exceedance probability curves with P90, P50, and P10 reporting WELL TEST & TOOLS - Choke flow: gas mode (Gilbert, Norsok, TAM, SLB) and oil mode (Gilbert, Ros, Baxendell, Achong) - AGA-3 orifice metering for gas and ISO 5167 for liquid - Gas flowline pressure drop: 30-segment Darcy-Weisbach with PR-EOS properties at each segment, plus Weymouth and Panhandle B empirical methods - Petrophysics: Archie equation with density, sonic, and direct porosity methods, Pickett plot - Gas heating value and composition - Pipe capacities database (tubing, casing, drill pipe) - Unit converter with HC equivalents, reciprocal GOR/CGR, and density-gradient conversions DESIGNED FOR THE FIELD - iPhone-first interface with iPad responsive layouts - Oilfield and Metric unit systems with one-tap toggle - Share results and charts via email or messaging - Available in English, Norwegian, French, Chinese, Spanish, and Arabic - Works fully offline - no internet connection required - PVT properties flow between modules automatically All calculations use published, peer-reviewed methods from SPE literature and industry-standard references. No proprietary correlations, no curve-fitted shortcuts. Tabular data exports let you paste results directly into Excel or Google Sheets.

About

PDF to ePUB

This tool converts PDF documents into reflowable ePUB ebooks directly on your device, ensuring complete privacy. It offers high-quality formatting, simple one-tap conversion, and cross-device compatibility within the Apple ecosystem.

Highlights
  • Local PDF to ePUB conversion
  • Preserves document formatting
  • One-tap conversion process
  • Cross-device Apple ecosystem support
  • Multiple subscription plans
  • Ad-free experience
Features
Read full description

PDF to ePUB Converter transforms your PDF documents into beautifully formatted ePUB ebooks — entirely on your device. No cloud uploads, no servers, no data ever leaving your iPhone, iPad, or Mac. YOUR FILES STAY PRIVATE Unlike other converters that upload your documents to remote servers, PDF to ePUB processes everything locally. Your sensitive documents, personal notes, and confidential files never leave your device. Zero network calls during conversion. Complete privacy by design. BEAUTIFUL EBOOK OUTPUT Our advanced conversion engine preserves your document formatting while creating clean, reflowable ePUB files optimized for any e-reader: - High-quality text extraction with proper paragraph structure - Smart chapter detection for easy navigation - Image preservation with optimal sizing - Clean, readable typography in every converted ebook - Valid ePUB 3.0 output compatible with all major readers SIMPLE ONE-TAP CONVERSION Converting your PDFs has never been easier: 1. Select or drag in your PDF file 2. Tap Convert 3. Get your ePUB instantly Share your converted ebooks directly to Apple Books, Files, or any app. Preview your ePUB right inside the app before exporting. WORKS EVERYWHERE YOU DO Designed for the entire Apple ecosystem: - iPhone: Convert on the go - iPad: Side-by-side conversion with split view support - Mac: Full desktop experience with keyboard shortcuts and drag-and-drop FLEXIBLE PLANS Choose the plan that works best for you: - Weekly: 10 conversions per week - Annual: 50 conversions per year (best value) - Lifetime: Unlimited conversions forever AVAILABLE IN YOUR LANGUAGE Full support for English, Spanish, French, German, Portuguese, Japanese, Korean, and Chinese (Simplified). DESIGNED WITH CARE A clean, modern interface with dark mode support, smooth animations, and accessibility features including VoiceOver and Dynamic Type. No cluttered screens, no intrusive ads - just a premium tool that does one thing exceptionally well. Download PDF to ePUB Converter today and start reading your PDFs the way they were meant to be read. Privacy Policy: https://winmail-dat-opener-viewer.blogspot.com/p/pdf-to-epub-converter-privacy-policy.html Terms of Use: https://winmail-dat-opener-viewer.blogspot.com/p/pdf-to-epub-converter-term-conditions.html

Screenshots

ResToolbox34 screens
PDF to ePUB4 screens

Verdict

The call

The clearest difference is in-app purchases: ResToolbox3 at none against PDF to ePUB's 3. On price, update cadence, ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. PDF to ePUB sells 3 in-app purchases, starting at $2.99 per 7 days. ResToolbox3 asks for nothing beyond the download.

UpkeepUpdate frequency

ResToolbox3 ships an update every 6 days, PDF to ePUB every 2 weeks. Both last shipped on October 31, 2026.

Scorecard2 real differences · 8 level
ResToolbox3 versus PDF to ePUB: the parameters behind the verdict, then further details
ParameterResToolbox3PDF to ePUB
PriceFreeFree
Rating5.0 (2 ratings) — better—
Positive reviews—0.0% of reviews
Number of ratings2 — better—
Update frequencyEvery 6 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS15.015.0
Further details — not scored
Size25 MB27 MB
Age rating4+4+
DeveloperMobileReservoirOMER FARUK KIZILTUG

Customer experience

ResToolbox3

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

PDF to ePUB

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

ResToolbox3

No in-app purchases

3 purchases

PDF to ePUB

Subscriptions2
  • Weekly Premium$2.997 Days
  • Annual Premium$19.991 Year
One-time1
  • Lifetime Premium$24.99

Questions

Is ResToolbox3 free?
ResToolbox3 is free to download, with no in-app purchases.
Is PDF to ePUB free?
PDF to ePUB is free to download, with in-app purchases available.
Do ResToolbox3 or PDF to ePUB have ads?
Neither ResToolbox3 nor PDF to ePUB shows ads.
Which is updated more often, ResToolbox3 or PDF to ePUB?
ResToolbox3 ships an update every 6 days, and PDF to ePUB every 2 weeks. Most recently, ResToolbox3 was updated on October 31, 2026 and PDF to ePUB on October 31, 2026.

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