The free app has been created by Grapple Mobile and is available for iPhone, Android and Blackberry platforms.
The app features three of the Post Office's current online services. The Post Office branch finder uses mobile phone GPS information to plot a route to a consumer's nearest branch.
Consumers can also search for addresses and postcodes through the app and perform currency conversions using the Post Office Travel Money exchange rates.
A spokesperson for the Post Office, said: "This latest addition to our current portfolio of digital services enables customers to perform selected simple functions, quickly and easily, while on the move."
Martin Moran, the Post Office's head of financial services, has been acting as the company’s marketing director since the beginning of this year, filling in for Gary Hockey-Morley while a replacement is found.