Cost Index vs QT Random Number Generator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Cost Index
This app helps airline and corporate aircraft operators achieve significant operational savings by calculating the optimum cruise speed for flights based on pilot-inputted conditions and aircraft-specific data. It offers advanced features for cost, fuel, and time optimization, including level change analysis and turbulence margin adjustments.
- Optimum cruise speed calculation
- Customizable operational data display
- Minimum fuel burn speed for long range
- Turbulence margin adjustment
- Level change analysis for climb/descent decisions
- Automated data updates
Read full descriptionHide full description
Cost Index is an app designed and developed by airline pilots, for airline and corporate aircraft operators. It enables, and has been proven to achieve, significant operational savings. Cruise flight conditions are input by the pilot, then complex algorithms calculate an exact cruise speed which will result in the minimum possible cost for a flight. i.e the optimum cost. Calculations are performed using a tailored aircraft specific data model and customer specific operational costs. Pilots can vary flight level, wind, temperature, weight, and sector cruise distance to find the optimum indicated airspeed and/or mach number. Time difference between optimum cruise speed and minimum time speed can be displayed. Pilots can modify the optimum speed either directly or by decreasing/increasing the time difference. This functionality allows a speed to be selected that will achieve an on-time arrival should this be an overriding factor in the operation. Information displayed on the "Cruise Speed" and "Detail" pages can be customised for the operator. There are over 150 parameters that can be displayed on either of these pages, which can be constructed so that crew do not see any sensitive operational data. As an operational planning/costing tool, all parameters can be made available within the administrator account. For sector lengths approaching the maximum operating range of the aircraft type, a speed for minimum fuel burn is calculated. This speed is better than long range cruise as it takes into account the wind component. When the app detects buffet margin data, a turbulence button is displayed that increases the buffet margin from 1.3g to 1.6g if selected ON. "Level Change" provides unique functionality to aid crew when deciding whether to climb or descend for operational reasons such as turbulence or strong headwinds. There are two features. The first displays the difference in total costs, fuel burn and time, for each flight level when compared to the selected flight level (all other variables the same). The second feature displays the wind required at each level to break even with total cost when compared to the selected level. The flight level with optimum total cost, which is usually the highest achievable level, is highlighted in black with green text. "Downloads" gives the ability to force data updates, although the app will attempt to update it's operational data once it becomes 24 hours old. The number of days since the last update is displayed on the "Downloads" tab badge and also the app icon badge to remind pilots to update the data whilst on the ground. The page has a message area which can display text entered by the administrator. It could be used to promote a flight efficiency programme by giving crews feedback / updates on real savings achieved and tips on new efficient operating techniques. The "Settings" tab is only available to administrator accounts. Its use is for updating operating costs but also includes some customisation functionality. For demonstration purposes, the app has four downloadable sample data sets which contain fictitious data. The following devices are supported: iPad, iPad Retina, iPhone, iPhone Retina 3.5-inch, iPhone Retina 4-inch and iPod Touch. To setup an account for your operational fleet, please contact Flight Efficiency Limited. For more information email: help@flightefficiency.co.uk
QT Random Number Generator
Generate random numbers quickly and easily for various purposes. This app offers a clean interface and accurate results without requiring an account or internet connection. It's perfect for games, decision-making, or any situation needing a random outcome.
- Generate random numbers
- Set maximum value
- Clean, modern interface
- Quick and accurate results
- No account required
- Works offline
Read full descriptionHide full description
QT Random Number Generator is a fast, simple, and easy-to-use app for generating random numbers anytime you need them. Choose your maximum value and instantly generate a truly random number. Whether you’re picking a winner, making a decision, running a game, or just need a quick random result, this app gets the job done with no distractions. - Clean, modern interface - Quick and accurate random results - No account or setup required - Works offline - Lightweight and easy to use Perfect for games, giveaways, contests, classrooms, decision-making, and everyday use.
Screenshots
Verdict
The clearest difference is ads: Cost Index at none against QT Random Number Generator's shown. Cost Index also leads on monetization model (free vs ad-supported) and iOS requirement (8.0 vs 17.6). QT Random Number Generator's advantage is ratings volume (5 vs 1). On price, rating, update cadence 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for Cost Index against 5.0 for QT Random Number Generator. That said, the two scores are not equally well evidenced: QT Random Number Generator has 5 ratings behind it against 1, so its average is the more settled of the two.
Cost Index ships an update every 16 months, QT Random Number Generator every 11 months. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.
| Parameter | Cost Index | QT Random Number Generator |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (5 ratings) |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 1 | 5 — better |
| Update frequency | Every 16 months | Every 11 months — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 8.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 3 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | Flight Efficiency Limited | Web Services Utah LLC |
Customer experience
Cost Index
QT Random Number Generator
In-app purchases
Cost Index
No in-app purchases
QT Random Number Generator
No in-app purchases
Questions
Is Cost Index free?
Is QT Random Number Generator free?
Which has better reviews, Cost Index or QT Random Number Generator?
Do Cost Index or QT Random Number Generator have ads?
Which is updated more often, Cost Index or QT Random Number Generator?
Other comparisons















