How can I change my iPhone default browser?
iOS on both the iPhone and iPad offers no ability to specify one of the many Mobile Safari alternatives as your device's default browser.
Owners that have jailbroken their iPhone can add this functionality by installing an iOS tweak called Browser Changer, which is the successor to OpenOpera. There's also an SBSettings toggle available for Browser Changer, allowing for quick and easy default browser changes.
Browser Changer comes with support for over 25 alternative browsers, including popular alternatives to Mobile Safari such as Dolphin, Atomic Browser, Opera Mini and more.
To install the Browser Changer tweak, open Cydia, select 'Search' and type in "Browser Changer". The rest is self explanatory.