1. Build a teaser website. Do this a month or two before your launch to collect email addresses of people who would like to know when the app launches.

2. Share your content. Use your Twitter, Facebook, Google+ and LinkedIn profiles to promote the app several times in a week.

3. Create a product video. Make it creative, funny, thought-provoking or personal. Tell the story, but in a way people can identify with. Here's a great one as example from the Dollar Shave Club.

4. Get press, tons of it. Entrepreneur Neil Patel says: "Press is the best way to kick start your startup, and the best way to get it is to manually reach out to journalists."

5. Pitch to app review websites. Sites like 148apps, App Store Apps and App Advice can generate a lot of buzz for your app if they mention it.

6. Contact bloggers who would care. Identify bloggers who write on niches that relate to your app. For instance, a children's app can be pitched to bloggers.