Opera Software has made available their Opera Mobile Emulator as a free download from the Mac App Store.
It is a free download and is aimed at web developers who want to test out their websites on Opera’s mobile browsers.
Opera spoke about this app:
The Opera Mobile Emulator allows you to run Opera Mobile on your Mac, making web development for mobile phones and tablets a breeze. Use the launcher to spawn multiple Opera Mobile instances with a defined resolution, pixel density, input mode and more, and save your settings as profiles for future testing. Connect the Opera Mobile Emulator to Opera Dragonfly and do your mobile CSS, JS and performance debugging using a powerful developer toolkit.