Imo, if my box comes preloaded with all those apps channels etc, i immediately uninstall them. Then i installed those what i usually use eg CinemaHD / CyberflixTV, CyroseHD (official), a few backups such as TeaTV / TyphoonTV.
As for 'proper' apps, there's Stremio (an excellent streaming app which uses torrent, so u need a vpn such as ExpressVPN or u can even use a free vpn such as 1.1.1.1 app). Fyi, I'm using umobile GX30 hotspot, so streaming torrent speed average 1MB/s is good enough for Stremio. The more seeders, the faster and smoother the movie plays. Also I installed iFlix, AstroGo, and UnifiTV.
For live tv (MyFreeview local broadcast), i use Tivimate or OTT Navigator, or even Kodi for that matter. Speaking of Kodi, there are a few K-Drama addons for the wife, (lcdrama & Dramago).
Lastly, youtube wise, obviously the Smart Youtube TV app.
The rest, ES File Explorer file manager, WinRAR, ShareIt, PDAnet, Internet Speed Meter (to display the net speed, i placed it at the top right corner, so I can easily monitor my net speed).
Very good reference summary for a newbie like me.
Dont mind if i ask, what tv box are you using? I thought unifitv is not compatible with android tv box?