You need to figure out the value proposition for the customer segment you will be serving.

1. So the first thing you are going to do is figure out what problem your app solves for your ideal customer segment.
2. You then need to create and understanding of what activities will be involved for you to provide that value(ex. development of the app or create partnerships with "X").
3. Then you need to study your market
4. Once you have a understanding of the above you can begin to formulate pricing strategies with your segments in mind.

Also, keep in mind this is really important for you, so will the marketing expenditure and the branding, look up churn rates on apps in the first 3 months.

Call me if you need help.