As listed on each trailer chapter I've posted, all of them are made using the Windows program Sony Vegas Pro 13. None of them are made using apps, sorry! I'm not familiar with phone editing beyond iMovie so I won't be able to recommend apps for you to try to make trailers of your own.

I find my movies/episodes from sources on Twitter (super easy to find— just search 'thing you want 1080p' and you should find a source, or search 'logoless thing you want'). Even if you don't have Twitter, you can probably find a source, but most accounts are private so you need an account to request a follow.

You can also find clips from YouTube by searching "_____scenes" and you should be able to find some, especially if they're well-known characters. Then, search for a website that can download videos from YouTube, and there you go!

I additionally use stock footage in some of my trailers. For example, in my trailer for Havoc, I used clips of NYC in the fall and placed them at the beginning. Sometimes stock footage can make your trailer look more realistic because it looks as it it's part of the "film" and often introduces the setting! You can find footage on basically anything— from coffee shops, to animals, to explosions, to various cities around the world.

I use a plethora colorings that I've downloaded from YouTube, and credit is always given in the trailer chapter/description on YouTube as well. My favorite ones are made by DarkestHearts, Nuur Salvatore, and Charizzaard.

Do I take trailer requests? No. like I said in my previous answer, I am very busy and trailers take me a very long time to make. The PC I use is old and takes forever to play back what I've edited due to lagging, but it takes even longer to render files into video format. I simply don't have the time to constantly make people trailers and get stuck in the hair-pulling, frustrating routine that is creating one.

Edit: Well, I'm 99% sure that my Windows laptop has fully died, so I'm ~unable~ to make trailers anyway.