The TRADE IT iOS SDK by TRADE IT interacts with the API to access financial features, that can be implemented into portfolio applications. Usage demonstrates developers how to specify parameters such as positive integers, buy & sell, and market & limit.
The Open Exchange Rates API currently provides real-time, hourly-updated exchange rates and historical data for 161 world currencies that can be used in web and mobile applications, frameworks and with any programming language.
It's hard to get excited about developing applications if there's no payoff for your efforts. That's the general consensus arising among makers of Windows Phone applications, who are dissatisfied with the poor sell through of advertisements. With no money coming in from ads, some developers say they'll have to start charging for their apps - or quit supporting Windows Phone.