This may be an old and trivial question but I have been struggling to find out which tool should I use to create the artwork (icons, images, logos etc) for my iOS apps? Can somebody here share their first hand experience and suggest some tools (preferably free) to do the job?
Whatever tool you use, be sure to design your artwork using vectors - iOS requires graphic assets in a variety of sizes, and you don't want to design, say, an app icon and realize later that you need a larger one, but have to redo your icon because your source wasn't a vector. After all, you never know when Apple might need a new size (for example, the new iPad and the retina sized splash screens).
Personally, I use photoshop to do my graphic work - mainly because it is a standard, though as long as your tool can generate pngs and jpgs, you should be fine. Just be sure it can handle scaling/zooming large images well as an iPad retina screenshot is 2048x1536 and it is unlikely your monitor will be ale to display it natively.