Calc4Key
by Khang Le
- Utilities
- Paid
- Zombie
- Rating
- 4.6
- 410 ratings · United Arab Emirates storefront
- Last update
- Sep 14, 2021
- Version 1.0.1
- Size
- 9 MB
- Category
- Utilities
- Tracked since
- Oct 10, 2026
Estimated revenue
A model estimate with a likely range, not a reported figure.
No estimate. Apps outside the grossing charts, and some countries, have no reliable rank-to-revenue curve, so we show nothing rather than a guess.
How this estimate is made
Rank: we take the app's best Top Grossing rank on the latest chart day. Category ranks are converted into an equivalent overall rank, because a #10 in Finance earns far less than a #10 overall.
Curve: that equivalent rank is read off a rank-to-revenue curve anchored on public company revenue and market-data reports for the US iPhone App Store.
Country: the curve is scaled per country (Japan is roughly a third of the US, Türkiye under 1%). Where we have no scale, such as China, there is no estimate.
Range: the likely range widens with country, category and chart depth. It is a plausible span, not a statistical confidence interval.
Not included: ads, payments outside the App Store, and any difference between gross sales and what the developer keeps. Low confidence means indirect data; medium means several independent sources agree.
Full methodScreenshots
As shown on the App Store listing.
About this app
Text from the App Store listing.
Use calculator directly on keyboard anywhere, anytime. No switch apps, no copy and paste results anymore!
You must enable the keyboard under system settings, then select it in your keyboard, using the globe button.
1. Open the settings app
2. Go General > Keyboard > Keyboards > Add New Keyboard
3. Add Calc4Key
4. Start typing in any app
5. Press "globe" icon to switch to the Key4Cal keyboard
6. Enjoy
What’s new
Release notes for the latest version, as written by the developer.
Fixed minor bug
Rank history
Daily position in the Libya charts. #1 is at the top.
- Best rank
- #4
- Current rank
- #5
- Days charting
- 7 of 7
On the charts today
Small & simple score
How realistic it is for a small team to build something like this.
68/100
Not flagged as small & simple
- Developer size10% · 25
Developer: 4 apps on the charts
- Audience size– · 20
No data, weight redistributed
- App size100% · 10
Size: 9 MB
- Price model100% · 15
Price model: paid
- Demand proof90% · 30
Best rank #4, 9 countries
An indicator, not a fact. We can't see team size. Calculated Oct 24, 2026 · method i2
How the score worksVersion history
- 1.0.1LatestReleased Sep 14, 2021