There are a fair few geographically-based ones around too - Dales, Cairngorms for exampe - search for 'app' in the search box at the top of the page and you should get some relevant articles.
Mammut has a packing list one - free - which some people may like. There are excellent Swiss free hiking trail ones too. Peaks, which names mountains using GPS, I like, but it can be a bit flaky on which hills it recognises.
I wish someone would produce a mountain weather forecast app and an avalanche forecast one, but so far, no go, although there is a Midge Forecast app out there. For weather, I rather like Weather Pro along with the Met Office. Check out the radar and pressure charts etc. You can often see rain coming your way, which is handy on the hill when you're working out whether it's a shower that's going to pass or the start of something sustained.
An iPhone (iToy) is a useless item to have with you out whilst out in the hills you wont even get a signal on it in a lot of areas compared to older 2G handsets, as with other 3G so-called "smart" phones what use are they if you can't even get a signal on them? How long do their batteries last as well for that matter?
A useful contribution from someone who clearly doesn’t own an iphone. An "iToy’s" reception for the most part is perfectly adequate and completely irrelevant in some respects as a reception is not required for GPS use as most decent applications cache the mapping. Although I wouldn’t want to use an iphone solely for navigation with a battery backup pack such as a mophie juice pack you would get more than enough battery life to use it as a dedicated gps in the hills.
