Nice app from what i can see on the appstore anyways. Do you guys have an android version for this(i use android myself), or is this an iOS only thing?
IMO you really need to add some other features than just a live ticker and candlestick chart. Your premium feature is offered for free in apps such as blockfolio which also has a portfolio tracking service. I'm not saying that your app is bad; it's just some advice. Think of something creative that will make every trader's life much easier.
Otherwise, good luck with your project. This should be moved to service discussion or project development, it does not belong in exchanges because it is not an exchange.