Check out the ideas I have proposed in the questions section. One of the important aspects of a successful product is to be very very specific about the scope of the product.
Today’s world is all about integrating and reusing code across apps and building an app on top of other apps instead of reinventing everything.
Leverage what’s already available and add lots of new functionality, awesome ideas and make the first version addictive to the user. Take feedback and quickly release the next version which already has a lot of planned stuff anyway. Keeping some features for the next release in addition to fixes of release 1 makes good marketing and business sense.