I have an idea for a complex mobile app. I would like to put the idea on kickstarter to get funded, but prior to that I need to calculate out exactly (or roughly) what it's going to cost in order to be funded properly. Due to the complexity, which may be on par with social media apps, I think I may need quotes from larger or more reputable companies rather than a mom-and-pop developer. How do I choose a developer? Where do I start? How do I know who is trustworthy?