I also work on PC's and have an iPhone and an iPad. I tried a number of PC GTD solutions and many ios apps and settled on Nozbe. I didn't like the costs at all for the apps- must by seperate ones for iPhone and iPad- and yearly service, but as they say you get what you pay for. It was set up with GTD in mind, has a great user interface, is very flexible, syncs across all platforms, and links with Evernote and Dropbox. Give it a try. Good luck!