The following iPhone apps are mostly only applicable in the UK;

Tivizen App - but you will need a Tivizen DVB-T WiFi receiver.

http://www.youtube.com/watch?v=NcfzriQigKE


Memory Map - 1:50,000 USGB DVD of the complete UK is available and maps are transferable to the iPhone, iPod Touch, iPad etc.

http://www.youtube.com/watch?v=EoNorronqFU



Other non-uk applicable apps;

Denon Audio App - Excellent audio app graphic equalizer and Internet radio.

https://itunes.apple.com/us/app/denon-audio/id520604518?mt=8



3CX app - turn you iPhone into a VIOP mobile phone and use a 3rd party VOIP provider

http://www.3cx.com/VOIP/voip-phone/


SPOT connect app - You will need a SPOT connect though.

http://www.youtube.com/watch?v=5Ar1niSpGWQ



If you find yourself in a poor reception area an unlocked MiFi which will take an external antenna for the various microwave frequencies bands to cover 2.5G, 3G and 4G networks could prove useful as a backup using another wireless network provider may prove to be invaluable. i.e. a high gain antenna could provide 10dBi or more signal gain

http://dx.com/p/1710-2170mhz-12dbi-direc...ma-female-37398

Not entirely portable for everyday use, but the external antenna's can be kept in a vehicle.

Edit.. A dual band microwave antenna for a ZTE MF60

http://www.amazon.com/T-Mobile-Hotspot-E...;keywords=zte60