O2 has introduced O2 TU Go, which is good news if you like the idea of pushing your communications across multiple devices.Confused? Let us enlighten you. The app is available to O2 pay monthly customers to use on an iPhone, iPad, Android device or a Windows 7 PC. If that's you, go get it now. Now, using your O2 number as identification, you can access your texts, calls and voicemail on any devices you have the app installed on. If you reply, it looks like it has come from your phone (rather than a tablet or PC for example). The people at the other end don't need the app, nor do they need to be on the O2 network. They're none the wiser to anything going on.Why is it a good thing? Well, if you haven't got your phone with you, you can keep in touch. Also, if you have no phone connectivity, but you are on a Wi-Fi network, you can keep in touch too. Reason enough to have it. But be warned - texts and calls made are not free. They look like they're from your mobile and they're charged to that account. That's the one big downside.You can use it on up to five devices at once, all of which have access to your address book and have a history of past communications/conversations. If all of that appeals, go get that app, which is available on your relevant app store.