Questions

Yes. No trial, no paid tier, no adverts, nothing held back behind a payment. It is a hobby project built on open data and open source, and the intention is to keep it that way. You do need a free account, see below what that is for.

Much as I hate it, yes you do. The only thing stored about you is your email address. No name, phone number, payment details or anything like that. Your account is only there so I can share your aircraft profiles between your devices, and so that I have an idea of how many individual users use the app. More detail on the privacy page.

JVFR is a PWA, which is a bit different from a 'normal' app. That is what lets one codebase run on iPhone, Android, Windows and macOS without three separate builds maintained by one person in his spare time. You install JVFR directly from the website. See the install guide.

Yes, if you download your area first. The chart and the aviation data are stored on your device. Anything inherently live like weather, NOTAMs or traffic obviously needs an internet connection, but actual navigation and GPS works offline.

You choose. Areas are downloaded as 1° tiles and JVFR shows the exact size before you download. A compact download of a small country is tens of megabytes, full detail over a large area runs to several hundred. You can delete any area at any time as well.

Airspaces, restricted areas, aerodromes and navaids come from openAIP, a community-maintained database. Packages are rebuilt on the 28-day AIRAC cycle and the app flags a package as out of date when a newer cycle is published. You can see what is currently published on the coverage page.

No. JVFR is not certified, it is maintained by one person, and the underlying data is community-sourced. Use JVFR alongside official charts and an official briefing, not instead of them. The safety notice is worth two minutes of your time.

Your position is used on your device to draw the map and log your flight. It is not sent anywhere. I haven't got a clue where any of you guys are from. See privacy.

No. It shows ADS-B and MLAT traffic from aggregator services, which means aircraft without a transponder, or out of receiver coverage, simply are not there. It is for situational awareness. Keep looking out of the window. If I ever figure out how to add ADSB in, that'd be neat, but currently it is not implemented.

Email info@jvfr.net. I try to keep everything running, but in my day to day life I am not monitoring all functions constantly.

That is the plan. The running costs are a domain and some hosting, and the data mostly comes from projects that give it away. It would feel wrong to profit off of open source data.

If you would like to help cover those costs, there is a buy me a coffee page. It is entirely optional and buys you nothing: no features are locked, and nothing about the app changes whether you use it or not. Supporting the projects the data comes from is arguably a better use of the money.