Holdover Calculator vs ATIS App
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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. • 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. Minutes and seconds below an hour; hours and minutes above. The wall-clock "Ends at" reference is 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 pilots' devices over a direct local Wi-Fi/Bluetooth connection; the captain approves every change, and the link re-establishes itself if a device drops out of range. No account, no internet, no server. • 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 — write a note and attach a screenshot; your report includes a summary of what you changed this session so issues get resolved faster. 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
ATIS App
Access real-time airport weather and operational information for major US airports. Receive instant notifications when critical updates are made. No account is required to view current data.
- Live Digital ATIS viewing
- Instant push notifications
- No account required
- Default airport setting
- Favorite airports
- Extensive US airport coverage
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ATIS App allows the live viewing of the most current Digital ATIS, or D-ATIS, information for major airports in the United States. You can view ATIS information with no account or signup required. You can also receive instant notifications of new airport ATIS information via push messages. Know exactly when the ATIS changes! This app is perfect for pilots, dispatchers, aviation enthusiasts, and other aviation personnel interested in weather and airport conditions at US airports. You can easily set a "default" airport that will automatically load whenever you launch the app, and you can favorite multiple airports for easy access to your most frequented airfields. Currently, the airports available include: • ABQ - KABQ - Albuquerque International Sunport • ADW - KADW - Joint Base Andrews • ALB - KALB - Albany • ANC - PANC - Ted Stevens Anchorage • ATL - KATL - Hartsfield Jackson Atlanta • AUS - KAUS - Austin Bergstrom • BDL - KBDL - Bradley • BNA - KBNA - Nashville • BOI - KBOI - Boise Air Terminal / Gowen Field • BOS - KBOS - Boston Logan • BUF - KBUF - Buffalo Niagara • BUR - KBUR - Bob Hope Airport • BWI - KBWI - Baltimore/Washington Thurgood • CHS - KCHS - Charleston Air Force Base • CLE - KCLE - Cleveland Hopkins • CLT - KCLT - Charlotte Douglas • CMH - KCMH - John Glenn Columbus • CVG - KCVG - Cincinnati Northern Kentucky • DAL - KDAL - Dallas Love Field • DCA - KDCA - Ronald Reagan Washington National • DEN - KDEN - Denver • DFW - KDFW - Dallas Fort Worth • DTW - KDTW - Detroit Metropolitan Wayne County • ELP - KELP - El Paso • EWR - KEWR - Newark Liberty • FLL - KFLL - Fort Lauderdale Hollywood • GSO - KGSO - Piedmont Triad • HNL - PHNL - Daniel K. Inouye Honolulu • HOU - KHOU - Houston Hobby • HPN - KHPN - Westchester County • IAD - KIAD - Washington Dulles • IAH - KIAH - George Bush Houston Intercontinental • IND - KIND - Indianapolis • JAX - KJAX - Jacksonville • JFK - KJFK - John F. Kennedy • LAS - KLAS - McCarran Las Vegas • LAX - KLAX - Los Angeles • LGA - KLGA - La Guardia • LIT - KLIT - Little Rock Adams Field • MCI - KMCI - Kansas City • MCO - KMCO - Orlando • MDW - KMDW - Chicago Midway • MEM - KMEM - Memphis • MIA - KMIA - Miami • MKE - KMKE - General Mitchell Milwaukee • MSP - KMSP - Minneapolis St. Paul • MSY - KMSY - Louis Armstrong Orleans • OAK - KOAK - Metropolitan Oakland • OKC - KOKC - Will Rogers World • OMA - KOMA - Eppley Airfield • ONT - KONT - Ontario • ORD - KORD - Chicago O'Hare • PBI - KPBI - Palm Beach • PDX - KPDX - Portland • PHL - KPHL - Philadelphia • PHX - KPHX - Phoenix Sky Harbor • PIT - KPIT - Pittsburgh • PVD - KPVD - Theodore Francis Green State • RDU - KRDU - Raleigh Durham • RNO - KRNO - Reno Tahoe • RSW - KRSW - Southwest Florida • SAN - KSAN - San Diego • SAT - KSAT - San Antonio • SDF - KSDF - Louisville Standiford Field • SEA - KSEA - Seattle Tacoma • SFO - KSFO - San Francisco • SJC - KSJC - Norman Y. Mineta San Jose • SJU - TJSJ - Luis Munoz Marin San Juan • SLC - KSLC - Salt Lake City • SMF - KSMF - Sacramento • SNA - KSNA - John Wayne Orange County • STL - KSTL - St. Louis Lambert • TEB - KTEB - Teterboro • TPA - KTPA - Tampa • TUL - KTUL - Tulsa • VNY - KVNY - Van Nuys Disclaimer: ATIS App should not be used as a flight planning tool. No warranty is implied or guaranteed as to the accuracy of the provided information. Plan flights using only FAA approved tools. Use of this app implies consent to this disclaimer.
Screenshots
Verdict
The clearest difference is rating: Holdover Calculator at 5.0 against ATIS App's 4.3. Holdover Calculator also leads on ads (none vs shown) and review sentiment (83% vs 64%). ATIS App's advantage is monetization model (free with in-app purchases vs subscription) and ratings volume (40 vs 1). On price, update cadence, in-app purchases 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
Both are free to download. Holdover Calculator sells 1 in-app purchase, starting at $9.99 per year and ATIS App sells 1 in-app purchase, starting at $4.99 per year. Whichever you choose, the download price is not the number that matters.
Holdover Calculator holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: ATIS App has 40 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 83% of Holdover Calculator's written reviews are positive against 64% of ATIS App's.
Holdover Calculator ships an update every 6 weeks, ATIS App every 2 months. The most recent releases landed on October 9, 2026 and October 20, 2026 respectively.
| Parameter | Holdover Calculator | ATIS App |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.3 (40 ratings) |
| Positive reviews | 83.3% of reviews — better | 63.6% of reviews |
| Number of ratings | 1 | 40 — better |
| Update frequency | Every 6 weeks — better | Every 2 months |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Subscription | Free with in-app purchases — better |
| Best chart rank | #198 — better | — |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Requires iOS | 26.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 24 MB | 40 MB |
| Age rating | 4+ | 17+ |
| Developer | Kilo Lima Management, LLC | iawix ltd. |
Customer experience
Holdover Calculator
ATIS App
In-app purchases
Holdover Calculator
- 1 Year Subscription7 Days trial$9.991 Year
ATIS App
- ATIS App Ad Free Subscription1 Year trial$4.991 Year
Questions
Is Holdover Calculator free?
Is ATIS App free?
Which has better reviews, Holdover Calculator or ATIS App?
Do Holdover Calculator or ATIS App have ads?
Which is updated more often, Holdover Calculator or ATIS App?
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