DDToolsPro vs Kyanite Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DDToolsPro
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This tool will help directional drillers and company men with day to day calculations for standard directional drilling and a segmented (survey) tool for curves! Terms of use : https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Kyanite Pro
This app offers a suite of offline drilling calculators and reference tools for oil and gas professionals. It includes features for mud engineers, cementers, and directional drillers, with options to share data with crews. A free tier provides basic tools, while a subscription unlocks advanced calculators and job sheets.
- Offline drilling calculators
- Mud, cement, and directional drilling tools
- Field notes and reference charts
- Crew data sharing
- Kill sheet and cement job sheet
- Chemical inventory management
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A professional calculation and reference tool for the people who run the well: drilling and mud engineers, solids control hands, cementers, directional drillers and MWD hands. The calculators work completely offline. No ads and no tracking, and no account is needed to use them. You only sign in if you want to share records with your crew. FREE TO START The scientific calculator, field notes, reference charts, volume tables and the hitch calendar are free, along with the full calculator catalog so you can see what you are paying for. KYANITE PRO Unlocks the 120+ field calculators, kill sheets, cement job sheets, LCM build sheets, location volumes and chemical inventory. Start with a 3-day free trial, then $3.99 per month or $19.99 per year. It all keeps working with no signal. SHARE WITH YOUR CREW Keep one set of figures in front of everybody on location. Share tank gauge readings, chemical inventory, notes, LCM build sheets, kill sheets and cement jobs with the hands you work with, and every phone stays in step. Anything you enter with no signal goes up as soon as you have coverage, and your own records stay private until you choose to share them. 120+ CALCULATORS Drilling engineering: capacities, volumes, string displacement, pump output and strokes, circulation times, hydrostatic, gradient, EMW, ECD, MAASP, lag time and ROP. Drilling fluids: mud weight conversions, oil/water ratio, weighted mixing, barite and hematite addition, dilution, PV, YP, gel strength, API fluid loss, retort solids and alkalinity. Solids control: solids percentage, low and high gravity solids, dilution and discard volume, screen mesh, centrifuge and hydrocyclone. Cementing: slurry yield and density, mix water, additives by percent BWOC, sacks, annular volume with hole excess, top of cement, balanced plug, displacement and strokes. Directional and MWD: minimum curvature, dogleg severity, interpolation, closure and vertical section, build and tangent sections, projections ahead, slide footage and toolface. Well control: formation pressure from SIDPP, kill mud weight, initial and final circulating pressure, the step-down schedule, maximum allowable mud weight from a leak-off test, MAASP, influx height and gas expansion. KILL SHEET A full IADC-style vertical well kill sheet you fill in before you need it. Keep the pre-recorded half current on a quiet tour; if the well is shut in, enter SIDPP, SICP and pit gain and the sheet works the kill with a full step-down schedule. CEMENT JOB SHEET Lay out a primary job end to end: capacities, coverage, barrels, sacks and mix water, the annulus drawn to scale, and a pump schedule with cumulative strokes. Casing presets from 20 to 4-1/2 inch. LCM BUILD SHEET Design a lost circulation pill product by product from your own inventory. Pounds, sacks, concentration and cost per barrel, a stock check against what is on hand, and one tap to record it as used. CHEMICAL INVENTORY A real daily ledger: previous, received, used, transferred in and out, and adjustments for every product, every day. Tomorrow starts where today finished and historical days are never overwritten. BUILT FOR THE FIELD Large touch targets and big monospaced results, readable in gloves and in the sun. Dark and light mode, favorites and search. ENGINEERING INTEGRITY Every calculator shows its equation, units, assumptions and a verification status: VERIFIED, NEEDS VERIFICATION or EQUIPMENT SPECIFIC. IMPORTANT Kyanite Engineering is a calculation and reference aid, not a well control program and not a substitute for engineering judgement. All results must be verified by qualified personnel. Well control decisions must follow the operator's and contractor's program and the person in charge on location. Subscriptions renew automatically unless cancelled at least 24 hours before the period ends. Terms: https://qd9gebwlsmhsi73ipf973-web-kyanite-support.rork.live/terms Privacy: https://qd9gebwlsmhsi73ipf973-web-kyanite-support.rork.live/privacy
Screenshots
Verdict
The clearest difference is price: Kyanite Pro at Free against DDToolsPro's $9.99. Kyanite Pro also leads on update cadence (weekly vs every 2 months). On ads, in-app purchases, 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
Kyanite Pro is free to download; DDToolsPro costs $9.99 up front. DDToolsPro sells 2 in-app purchases, starting at $12.99 per month and Kyanite Pro sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.
DDToolsPro ships an update every 2 months, Kyanite Pro weekly. The most recent releases landed on September 14, 2026 and September 12, 2026 respectively.
| Parameter | DDToolsPro | Kyanite Pro |
|---|---|---|
| Price | $9.99 | Free — better |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 2 months | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Freemium |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.2 | 18.0 — better |
| Further details — not scored | ||
| Size | 8 MB | 40 MB |
| Age rating | 4+ | 4+ |
| Developer | Michael Blake | Mike Haynes |
In-app purchases
DDToolsPro
- DD Tools Pro Unlock - Monthly$12.991 Month
- DD Tools Pro Unlock - Annual$129.991 Year
Kyanite Pro
- Kyanite Pro Monthly3 Days trial$3.991 Month
- Kyanite Pro Yearly$19.991 Year





