If you have a business that is likely to be capital intensive, I would raise seed capital as early as possible. Sure, some VCs want this and some Angels want that, but that's a generalization and you could certainly find the right investor with enough diligence to seek them out.

Before you seek funding you need to ensure you're buttoned up with your business plan and proof of concept. If you're app is new, but carries some similarities to others, then use that competitive knowledge to frame up the opportunity for an investor. A savvy and aggressive investor doesn't need to see every nut and bolt to evaluate an opportunity, but they do need to gain an understanding of where you fit into the market place in order to have a perspective on market potential. Good luck.