US navy pilot Dalton invented the WW (E6B) and I believe he was a genius in his time with the 'computer' being one of the most significant developments in aviation in the last century. However I think that is where it belongs - ever since the US opened up GPS to the world after the first Iraq war, navigation was always heading in a different direction. Whilst I think it is important to be able to read a map and track a course whilst flying and hence learning the basics of navigation, it is now time to go with technology. I thnk it is irresponsible of the CAA not to have any GPS training in the PPL - nick ritter (posted above) and I passed our PPL at roughly similar times and both spent mcuh effort trying to learn and programme mobile GPSs - being the way naivigation is going I really think this should be in the course.
As per apps - I know plenty who have used some of the very helpful apps over the WW in the exams but I think you need an understanding examiner, as the CAA is very clear they are not allowed, I would not advertise the fact if you use them. But they are certainly more relevant. Speaking form my own experience - I have not used the WW since the navigation exam and would have no idea how it worked any more, slightly worrying considering I am going to start reading for the IMC..... My advice would be use the iphone and find a friendly examiner - it might be bending the rules but long term a lot more practical for you.