Comparison

TallyRig vs HydroTech Pocket Engineer

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

Head to head
About

TallyRig

This app provides a suite of 17 oilfield and drilling calculators designed for field use. It features a digital tally-book history to save and share results, with offline functionality and a user-friendly interface for rig environments. Supports multiple languages and unit systems.

Highlights
  • 17 oilfield & drilling calculators
  • Digital tally-book history
  • Offline-first functionality
  • Sunlight Mode for outdoor readability
  • Glove-friendly interface
  • Formula review and show-work
  • Imperial and Metric unit support
Features
Read full description

17 oilfield & drilling calculators — with a digital tally-book history. TallyRig is a focused, field-ready calculator set for drilling and well control workflows. Run the essentials fast, save every result, and share a clean record when you need it. DESIGNED FOR THE RIG • Sunlight Mode: high-contrast screens you can read outside • Glove-friendly: big targets, minimal tapping • Offline-first: works without a signal • Trust the math: review the formula / show-work for each result 17 FIELD CALCULATORS, ORGANIZED BY CATEGORY • Well Control: Kill Sheet (Wait & Weight), Kick Tolerance, Gas Migration, Trip Fill, BOP Check (API Std. 53) • Pressure: Hydrostatic, EMW from Pressure, ECD • Fluids: Mud Weight-Up (barite), Slug, Cementing • Tubulars: Pipe Tally, Buoyancy, Capacity, Stuck Pipe (Free Point) • Hydraulics: Pump Output, Flow, Annular Velocity, Bottoms-Up • Utilities: Oilfield Unit Converter FIND TOOLS FAST Search, category filters, and a drag-to-arrange dashboard so your most-used calculators are always on top. HISTORY THAT'S ACTUALLY USEFUL • Save any calculation to a clean history timeline • Share a result card or a history record with your team • Sync across devices via iCloud (when enabled) UNITS Switch between Imperial and Metric (SI) where supported. Languages - Full in-app translation in English, Português (Brasil) and Español — including every calculator, result view and formula label. Switch any time in Settings → Language. WHO IT'S FOR Drilling engineers, toolpushers, drillers, mud engineers, wellsite supervisors, and well control trainees who want a fast, reliable pocket reference. IMPORTANT TallyRig is a calculation aid for reference and cross-checking. Always verify inputs and outputs and follow your company procedures and training.

About

HydroTech Pocket Engineer

Features
Read full description

HydroTech Pocket Engineer gives field operators and engineers instant access to essential pipeline and nitrogen calculators directly from their phone. Built for real-world jobsite conditions, Pocket Engineer is designed to deliver fast, accurate results when timing, safety, and precision matter most. Whether you’re planning a job, verifying calculations in the field, or making quick decisions under pressure, this tool puts HydroTech’s proven calculation methods in your pocket. Key Features • Pipeline volume calculations for fast job planning • Nitrogen calculations for purging and testing • Clean, mobile-friendly interface built for field use • Instant access with no complicated setup • Always up to date with the latest HydroTech tools Built for the Field Pocket Engineer is designed for operators, technicians, and engineers working in pipeline testing, pre-commissioning, and field operations. It eliminates the need for manual calculations and reduces the risk of error in critical workflows. Powered by HydroTech Developed by HydroTech Testing, this app extends the same tools and methodologies used on active job sites into a simple, mobile-first experience.

Screenshots

TallyRig4 screens
HydroTech Pocket Engineer3 screens

Verdict

The call

The clearest difference is in-app purchases: HydroTech Pocket Engineer at none against TallyRig's 1. HydroTech Pocket Engineer also leads on update cadence (monthly vs every 3 months). On price, ads, device support and iOS requirement 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. TallyRig sells 1 one-off in-app purchase. HydroTech Pocket Engineer asks for nothing beyond the download.

UpkeepUpdate frequency

TallyRig ships an update every 3 months, HydroTech Pocket Engineer monthly. The most recent releases landed on October 31, 2026 and October 28, 2026 respectively.

Scorecard2 real differences · 7 level
TallyRig versus HydroTech Pocket Engineer: the parameters behind the verdict, then further details
ParameterTallyRigHydroTech Pocket Engineer
PriceFreeFree
Rating4.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyEvery 3 monthsMonthly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size33 MB3 MB
Age rating4+17+
Developer嘉炜 丰michael schricker

In-app purchases

1 purchases

TallyRig

One-time1
  • TallyRig Pro$14.99
None

HydroTech Pocket Engineer

No in-app purchases

Questions

Is TallyRig free?
TallyRig is free to download, with in-app purchases available.
Is HydroTech Pocket Engineer free?
HydroTech Pocket Engineer is free to download, with no in-app purchases.
Do TallyRig or HydroTech Pocket Engineer have ads?
Neither TallyRig nor HydroTech Pocket Engineer shows ads.
Which is updated more often, TallyRig or HydroTech Pocket Engineer?
TallyRig ships an update every 3 months, and HydroTech Pocket Engineer monthly. Most recently, TallyRig was updated on October 31, 2026 and HydroTech Pocket Engineer on October 28, 2026.

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