SeafarersCalc
by simon french
- Finance
- Paid
- Zombie
- Small & simple · 94
- Rating
- 3.8
- 27 ratings
- Top 85%among 117 Finance apps
- Last update
- Jan 18, 2018
- Version 1.5.4
- Size
- 4 MB
- Category
- Finance
- 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.
The Seafarer's Earnings Deduction (seafarer's tax) eligibility calculator. SeafarersCalc allows quick and easy checking of voyage dates to determine whether they meet the half-days rule. As the dates are entered, a 'traffic light' indicator shows whether the voyage is valid or invalid. Once a set of valid dates is entered, the eligible voyages go green and you should make a claim.
What’s new
Release notes for the latest version, as written by the developer.
Application performance improvement.
Rank history
Daily position in the UK charts. #1 is at the top.
- Best rank
- #4
- Current rank
- #4
- 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.
94/100
Small & simple
- Developer size100% · 25
Developer: 1 app on the charts
- Audience size100% · 20
Ratings: 27
- App size100% · 10
Size: 4 MB
- Price model100% · 15
Price model: paid
- Demand proof80% · 30
Best rank #4, 3 countries
An indicator, not a fact. We can't see team size. Calculated Oct 25, 2026 · method i2
How the score worksVersion history
- 1.5.4LatestReleased Jan 18, 2018