I currently have a FR24 feed for the commercial application side. It works well for me professionally, but for entertainment purposes prefer ADSBx. The FR24 business features are important to me, just not $499 per year important. My FR24 feed defers that payment. Reading the ADSBx documentation, it appears that it's not cool to use a FR24 image to feed ADSBx. However, it looks like an ADSBx image can feed FR24 with out any problems. Is this correct? "The ADSBx image will feed FA, FR24, and all other ADS-B sites if you install their respective feeder clients."
If you are competent enough to change the FR24 config settings, then you can use the ADSBx script method to feed ADSBx. --net --net-bo-port 30005 pass those to dump1090 either through the web config or the /etc/frf24.ini Any reason that FR24 is useful? They block traffic, fake a lot of traffic, and are one of the more obnoxious sites to the community. They sue anyone who uses photos from JetPhotos.net, etc etc.
Alternatively to using the builtin fr24feed dump1090 (like described by james using --net and so forth), you can change the image to use a newer version of dump1090: https://github.com/wiedehopf/adsb-wiki/wiki/Bundle-install-for-dump1090fa Sometimes fr24 images are a little annoying, having the file system read-only because one of their scripts has a bug. (my install script above fixes that problem) After using that install you can install any feed client which works off port 30005 (that includes the ASDBx script method).
I agree; they are obnoxious. However, their "fleets" feature with the business plan is pretty handy. Their iPhone and Apple watch apps are handy to know when my planes takeoff when I am away from my desk. I'd love to look at alternative if you know of one.