Many of these are USA based. But I’m not sure where else to dump them lol.

Flight

https://opensky-network.org/

https://github.com/woheller69/planeSpotter

https://apt.izzysoft.de/fdroid/index/apk/eu.darken.apl

https://github.com/d4rken-org/airplanes-live-app

https://www.adsbexchange.com/

https://opentransitsoftwarefoundation.org/

Trains

https://trackyourtransit.com/

Marine

https://www.marinetraffic.com/

ISS

https://filbot.com/international-space-station-tracker

https://issinfo.net/

https://www.astroviewer.net/iss/en/observation.php

https://www.heavens-above.com/

https://www.nasa.gov/spot-the-station

Complicated stuff

https://open-ais.org/

https://www.aishub.net/