Comparison

Holdover Calculator vs Bumpwise

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

Head to head
About

Holdover Calculator

This tool simplifies the calculation of aircraft de-icing fluid holdover times. It offers manual input or automatic weather data retrieval for quick and accurate results. The app provides alerts for expired times and includes a pre-takeoff check timer.

Highlights
  • Accurate holdover time verification
  • User-friendly input display
  • Automatic METAR weather retrieval
  • Location-based METAR search
  • Active holdover time countdown
  • Audible and visible expiration alerts
  • Pre-takeoff contamination check timer
Features
Currently charting
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Holdover Calculator is a pre-departure decision tool for pilots facing winter operations. It returns the applicable anti-icing holdover or allowance time from FAA or Transport Canada published guidance, based on the actual weather, the de/anti-icing fluid applied, and your aircraft configuration. DESIGNED FOR iOS 26 Built for iOS 26 and its Liquid Glass interface. The pilot answers a sequence of focused questions; the app shows the matching table cell, the published range, and a continuously interpolated estimate within that range. KEY FEATURES • Holdover and allowance times from the current FAA Holdover Time Guidelines and Transport Canada HOT Guidelines — and if a correction is published mid-season, the app can pick up the new numbers on its own. Settings shows which set you are calculating with. • Live weather autofill via the NOAA Aviation Weather Center — closest METAR or any ICAO you search. • Manual entry always available when stations are out of range or you want to model conditions ahead. • All four fluid types (Type I through Type IV) with both generic-table and specific-brand selections. • Active Frost allowance and Ice Pellet allowance with a 90-minute takeoff-window tracker. • Chart Notes surfaced inline, with active conditions (cold-soaked wing, OAT thresholds, etc.) flagged so you see only the notes that matter right now. • App Estimated time — a continuous interpolation across OAT and precipitation intensity, shown alongside the FAA Recommended low end of every published range. • Countdown timer with Live Activity on the Lock Screen, with the wall-clock "Ends at" time always shown to the second. • Apple Watch companion for the crew member running the timer. • Cockpit Sync — share one running timer across the flight deck. Link two to four devices over a direct local connection; the captain approves every change. No account, no internet, no server. • On iPad and the open iPhone Duo, dock the holdover time and countdown beside your questions, on either side. • Readable on the ramp. Tap any advisory note — or any setting's description — to enlarge it in a comfortable card sized for reading-distance glasses. • Support & Feedback in one tap. Reach the developer from the menu with a note, a screenshot, and a summary of your session. No account required. • FAA or Transport Canada as the global default, with per-calculation overrides. • Local or Zulu time display; 12- or 24-hour clock. PRE-DEPARTURE DECISION ONLY This app is an advisor. The pilot in command remains solely responsible for verifying that the selected time is appropriate for the actual conditions, fluid, and aircraft at the moment of departure. Always cross-reference the current published holdover tables. DATA SOURCES • FAA Holdover Time Guidelines (current revision) • Transport Canada Holdover Time Guidelines (current revision) • NOAA Aviation Weather Center (aviationweather.gov) for live METAR observations SUBSCRIPTION Holdover Calculator is an auto-renewable annual subscription, with a free trial for new subscribers. Pricing is shown in the app before you subscribe. • Payment is charged to your Apple ID at confirmation of purchase. • The subscription renews automatically unless cancelled at least 24 hours before the end of the current period. • Your account is charged for renewal within 24 hours before the period ends. • Manage or cancel anytime in your Apple ID account settings. • Any unused portion of a free trial is forfeited when you purchase a subscription. PRIVACY Location is requested only to identify the nearest weather station; your coordinates are sent solely to NOAA to run that query and are never stored or shared with us. No ads, no analytics, no tracking. Privacy Policy: https://kilolimallc.github.io/legal/holdover-calculator/privacy.html Terms of Use (EULA): https://kilolimallc.github.io/legal/holdover-calculator/terms.html Disclaimer: https://kilolimallc.github.io/legal/holdover-calculator/disclaimer.html

About

Bumpwise

This app analyzes aviation and weather data to provide a minute-by-minute turbulence forecast for your specific flight. It offers a clear score, timeline, and explanations to help nervous flyers feel more confident.

Highlights
  • Flight-specific turbulence scoring
  • Minute-by-minute turbulence timeline
  • Live flight tracking
  • Guided calm breathing exercises
  • Global turbulence and weather map
  • Flight history and passport
Features
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PIONEERING TURBULENCE TECHNOLOGY Bumpwise does more than check the weather near your departure and destination. It analyzes conditions along the route your aircraft is actually expected to fly, and fuses multiple layers of aviation, weather, and flight data into a single forecast. The scoring engine draws on: NOAA turbulence and weather models Live pilot reports (PIREPs) AIRMETs and SIGMETs Convective weather advisories Winds aloft and jet stream conditions Flight schedules and route information Live aircraft position data Bumpwise builds a corridor around your route and estimates when your aircraft will reach each part of it, so forecast conditions are matched to where your flight will be at that moment rather than treated as one static weather snapshot. The engine then analyzes wind and gust intensity at takeoff and landing, vertical and horizontal wind shear, clear air turbulence indicators at cruise, turbulence model data, pilot reports, and active advisories. These signals become a minute by minute turbulence timeline, distilled into your flight's 0 to 100 score plus a separate score for the roughest section of the route. Forecasts refresh continuously and sharpen as departure approaches, so your numbers are most accurate in the hours before you board, exactly when you need them. WHAT YOU GET A 0 to 100 turbulence score for your specific flight A separate score for the bumpiest section of your route A phase by phase turbulence timeline from takeoff to landing A clear view of where smoother and bumpier conditions are expected Plain English explanations of what is driving your forecast Pilot reports and aviation advisories built into the score Live flight tracking along your route Automatic updates as conditions and flight status change A global turbulence and weather map BUILT FOR NERVOUS FLYERS When the seatbelt sign comes on, knowing helps, and so does having something to do. Bumpwise includes guided calm breathing you can follow right on screen, before or during your flight, even in airplane mode. Slow, paced breathing is one of the most reliable ways to settle your body's stress response, and pairing it with a timeline that shows when the bumps end changes how turbulence feels. YOUR PASSPORT Save flights to your personal Bumpwise Passport. Keep upcoming trips together, revisit previous routes, and build a history of every flight you have followed. FLY WITH MORE CONFIDENCE Flying feels stressful when you do not know what is coming. Behind the simple score is a forecasting system analyzing your route, timing, weather models, pilot reports, and live flight data, and turning all of it into one clear answer: what your flight is expected to feel like before you board. Check the air ahead. Know what to expect. Fly with more confidence. Terms of Use (EULA): https://bumpwise.app/terms-of-service Privacy Policy: https://bumpwise.app/privacy-policy

Screenshots

Holdover Calculator4 screens
Bumpwise4 screens

Verdict

The call

The clearest difference is monetization model: Bumpwise at free with in-app purchases against Holdover Calculator's subscription. Bumpwise also leads on update cadence (every 2 days vs monthly) and ratings volume (10 vs 1). Holdover Calculator's advantage is rating (5.0 vs 4.8) and chart position (#182 vs unranked). On price, 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

Both are free to download. Holdover Calculator sells 1 in-app purchase, starting at $9.99 per year and Bumpwise sells 3 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Holdover Calculator holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Bumpwise has 10 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Holdover Calculator ships an update monthly, Bumpwise every 2 days. The most recent releases landed on November 6, 2026 and November 10, 2026 respectively.

Scorecard7 real differences · 4 level
Holdover Calculator versus Bumpwise: the parameters behind the verdict, then further details
ParameterHoldover CalculatorBumpwise
PriceFreeFree
Rating5.0 (1 ratings) — better4.8 (10 ratings)
Positive reviews83.3% of reviews—
Number of ratings110 — better
Update frequencyMonthlyEvery 2 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationSubscriptionFree with in-app purchases — better
Best chart rank#182 — better—
DevicesiPhone, iPad, Apple Watch — betteriPhone
Requires iOS26.016.4 — better
Further details — not scored
Size24 MB102 MB
Age rating4+4+
DeveloperKilo Lima Management, LLCSnowflake Studio LLC

Customer experience

Holdover Calculator

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive83.3%
Neutral0.0%
Negative16.7%

Bumpwise

All ratings9 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

Holdover Calculator

Subscriptions1
  • 1 Year Subscription7 Days trial$9.991 Year
3 purchases

Bumpwise

Subscriptions2
  • Bumpwise Monthly$9.991 Month
  • Bumpwise Yearly$59.991 Year
One-time1
  • Single Flight Report$2.99

Questions

Is Holdover Calculator free?
Holdover Calculator is free to download, with in-app purchases available.
Is Bumpwise free?
Bumpwise is free to download, with in-app purchases available.
Which has better reviews, Holdover Calculator or Bumpwise?
Holdover Calculator is rated higher. Holdover Calculator averages 5.0 out of 5 from 1 ratings, while Bumpwise averages 4.8 from 10 ratings.
Do Holdover Calculator or Bumpwise have ads?
Neither Holdover Calculator nor Bumpwise shows ads.
Which is updated more often, Holdover Calculator or Bumpwise?
Holdover Calculator ships an update monthly, and Bumpwise every 2 days. Most recently, Holdover Calculator was updated on November 6, 2026 and Bumpwise on November 10, 2026.

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