---
title: "Support"
url: https://nostos.navoy.io/support
description: "How to get help, report a wrong figure, and the iOS app"
dataset: 2026.10.7 (2026-10-13)
license: CC BY 4.0
---

# Support

Nostos is a free tool by Navoy, on the web at nostos.navoy.io and as an iOS app. For help with either, email [info@navoy.io](mailto:info@navoy.io). Say which city, page or screen you are looking at and we will get back to you, usually within a few days.

## Useful pages

- [Methodology](https://nostos.navoy.io/methodology): how every score is calculated, formula by formula.
- [Open dataset](https://nostos.navoy.io/data): every number with its source, date and license, as one JSON file.
- [Visa guides](https://nostos.navoy.io/visas): who can apply, income, fee, processing time and where to apply, per country.

## Frequently asked

**Where do the numbers come from?** From open data: the WHO, the World Bank, M-Lab, NASA POWER, Passport Index and other published sources. Every value on a city page carries its source and date, and the [methodology](https://nostos.navoy.io/methodology) explains how a source value becomes a 0–100 score. Nothing is hand-tuned for a particular city.

**How do I change my passport or budget in the app?** Open the **You** tab and tap **Change passport, budget or weights**, or tap the filter button at the top of the **Rank** tab. The same sheet sets your region, months and factor weights. Your choices stay on your device.

**How do I report a wrong figure?** Email [info@navoy.io](mailto:info@navoy.io) with the city, the figure and, if you have one, a better source. The [dataset page](https://nostos.navoy.io/data) lists every source we use and when it was retrieved, so you can check what a number is based on. Fixes ship with the next dataset version, which the app picks up on its next refresh.

## The iOS app

The Nostos iOS app is in TestFlight. It shows the same cities and scores as the website, works offline from a bundled copy of the dataset, and refreshes from nostos.navoy.io when a newer version is published. See the [privacy policy](https://nostos.navoy.io/privacy) for what the app stores and sends.

HTML page: https://nostos.navoy.io/support