Where can find well Android Application Development ?
Which one do you need the application for? On which platform? I can recommend Innovecs company, their developers have big experience in different software development and can provide a big variety of options and decisions. You can find more info and look portfolio on www.innovecs.com/software-development-in-usa/ it is their website.
First of all I like mobile games because it's convenient for playing not at home! Now I'm playing legacy of discord and making it more interesting, I've used mods and got infinite money! How cool is it: you just enjoy and don't bother how to get money. A very good choice for people who just want to relax.
I think that first of all you should hire good designer very quickly. Also when your app will be ready I recommend you to take part in such competition project as www.webawards.top/ if yuo want to receive more and more subscribers and increase level of trust of your app all over the internet.