I have just been through getting a video ad on facebook, so I thought I'd add my experience to the database.
I won't go into extreme detail, use "help" articles for each step if needed.
I finished my project in C3, and used the internal tools to create the app bundle pack.
I then hosted my project via Google Play.
I went to Fiverr and hired a guy to make a video ad.
After all this, I wanted to advertise my app. So I went to facebook ad manager and started to create my ad.
It was at this point that additional requirements are added.
For this I used squarespace. I bought the domain and spent an hour changing things. [~$150]
Finally, back to facebook. You have to register your app with facebook before you can do an "Install Now!" ad. This is where I got hung up the longest.
When adding a platform (+platform), for me it was Android, it asks for the "Google Play Package Name"
This was the key moment when I finally got the facebook ad working.
In C3, under your projects properties, is a field called ID. For me it was "com.deltastarstudios.aretheyhiring"
This is the same ID name used on the google play store listing URL.
Entering this into the "Google Play Package Name" will register your app.
Going back to facebook ads, my app is now recognized and I can make the ad.
That was my experience. Ask any questions that you have.
But please, keep them limited to google play, android, and facebook.
edit: Getting a video ad on reddit is extremely easy