Nearly 25% of the UK population now have a smart phone.
The problem is these are split between 6 different operating systems, which means you would need 6 different apps to reach all market places, then you find that many corporate smart phones are locked, so the user can not access your app anyway.
The solution is simple, a mobile web app. A web site specifically designed to work on mobile devices to deliver your media based on the devices location.
On your Smartphone go to mobile.audio-guide.co.uk or scan the QR code on this page.