I basically gave up on finding a custom ROM for this TV so I'm looking for alternative TV apps to at least change the default app. Do you know if there is an app like this exist? It should work with satellite, I'm not looking for IPTV or streaming services, just something that supports plain satellite TV.

Edit: Currently experimenting with KODI, no luck yet though. If you also have suggestions regarding to it, I'm all ears.

Edit 2: KODI (and so Jellyfin, Plex etc.) needs a backend server for Live TV so add-ons alone won't work. According to KODI Wiki, currently there are no backends that work on Android. I also tried Google's older app called Live Channels but Google doesn't let you to run it because it's old ~~more useful~~.

Edit 3: I at least blocked ~~all~~ many of those ad streaming domains on pi-hole. Here is the regex I added to my blacklist. Maybe it will be useful for another poor soul who bought TCL TV.

^(.*\.)?(leiniao\.com|kedo-tclrestream\.b-cdn\.net|now\.amagi\.tv|huan\.tv|rttv\.com|kaltura\.com|plex\.tv|otteravision\.com|ads\.ottera\.tv|sofast\.tv|jwplayer\.com|fuelmedia\.io|molotov\.tv|mcncdndigital\.com|evrideo\.tv|aniview\.com|partytymestreaming\.com|playmoviesdfe-pa\.googleapis\.com|ov-static\.ottera\.tv|ottera\.tv)$

There are also some cloudfront domains however they use hash, so it's not possible to block the future hashes by now and they will appear again.