Before you register your company with the division of corporations, here are some things you might want to do.
Functional Prototype
This will go along way in determining the opportunistic value of your idea. There are some really great ideas that cost too much to develop and mantain, others that can be bootstrapped, and everything in between. A working demo will go a long way in helping to determine the technical complexity of your app.
Find Your Competitors
Understand your market and similar businesses in your sphere. Look for early stage startups and funded startups as well. They will have found ways to solve some similar challenges that you face.
Branding
Determine both the name of your business and secure a domain name. You will also probably need social media accounts and a logo.