It depends on who you think uses the app.
If you target the app at inexperienced ‘investors’ who are going to do 90% of their work on the app, then the app needs to deliver more to avoid the newbie questions, particularly bid/offer spread.
If you’re targeting experienced investors who will have spent 99% of their time using multiple third party tools, live prices and level 2 order books then fine, keep it simple, but then you need to be more precise with the contract prices.