Firefox is available for Android 2.2 and higher. See the Android System Requirements to check whether your Android phone is compatible with Firefox.
Firefox Home for iPhone
Firefox Home is a free application for the iPhone and iPod Touch. Firefox Home lets you access your Firefox desktop history, bookmarks and open tabs on your iPhone. Download it for free on iTunes.
Mobile Firefox for desktop computers
Developers can install mobile Firefox on Mac, Windows, or Linux PCs to test mobile web sites and add-ons. (The desktop versions are intended for development purposes only.)