Whew! I do my entire channel with the phone, so I have an INTENSE list of apps for you:
Video Editing: Kinemaster. Adobe Rush is good and there are some others, but Kinemaster is my fav.
Thumbnails/Channel Art: I Take a cool picture, color correct it in Snapseed and then run it through Picsart for text/overlays
Filming: I try to take advantage of all modern camera settings/features but if you don't have access to that Filmic Pro is awesome
Livestreaming: Prism Live is totally awesome, but the inability to do custom thumbnails, schedule streams and update meta-data renders it pretty useless unless you have lower-thirds, video clips etc ready to go for a livestream but for some reason are unable to schedule it in advance and don't care about thumbnail presentation. Streamlabs is a great option for overlays as it lets you pick up a scheduled stream, but honestly I have had issues with SL to the point I just use the YT App.
Analytics: Studio app is good, although it is better to access the Creator Studio using the mobile browser. Of course Tubebuddy is a powerhouse for tag research, batch comments, video performance etc. Nothing comes close.
Screen Capture: I use DU recorder if I need to capture my screen for a clip
Graphics/Animated Text: Alight Motion is SICK for this!
Music: I use FL Studio to make music and/or sound effects from time to time, though this is a whole 'nother level of work
Investment: Not YT related, but worth consideration. I use Acorns and Robinhood as a means of taking YT revenue and growing it. Helps that both offer financial compensation for pushing their product.
Podcast: I use Anchor for our podcast.
Now, Good Luck!!!