Do I need any special software?

No extra software needed.

Everything you need to build your iPhone app with you can access at www.freeiphoneappmaker.com, there’s no software to download and you can edit and update an app you’ve made online in the future just by visiting a special link that will import all of your iPhone app details back into the builder for you automatically. When accessing this website, we recommend using the Firefox internet browser or Safari, but Internet Explorer works okay too.