Feb 21, 2011 14:36 GMT  ·  By

Removed for undisclosed reasons as iOS 4.0 made its public debut, a Field Test Mode feature has been reintroduced in iOS 4.3 beta, an iPhone user running Apple’s latest iOS beta has found.

Described as "the full version of Field Test Mode," the returning function allows the user to quickly check the quality of the phone’s cellular signal by dialing *3001#12345#* and pressing Call on the iPhone.

In addition to this finding, a standalone FieldTest app was discovered as well.

The discoverer, quoted by Cult of Mac, details his experience:

“I was just performing a clear out of applications in my multitask bar on my iPhone, and I noticed one in there called ‘FieldTest’. This isn’t an application I’ve installed, and when I open it, it let’s me do some things I don’t understand.

An iOS Spotlight search brought up the app called ‘FieldTest’, and he also saw that app running in his task bar, according to the blog.

iOS 4.3 is currently still in beta testing. Apple has seeded registered developers with three separate betas since early January, all applicable on iPhones starting with 3GS, iPod touches starting with the third-generation, and the iPad.

Released through developer channels at the beginning of this month, iOS 4.3 Beta 3 is expected to reach its final stages of development momentarily.

Both the IPSW files and the iOS 4.3 Software Development Kit (SDK) builds reportedly contain references to unreleased Apple hardware, including several new iPads and iPhones.

The betas also bear indications that Apple’s camera-equipped iPad 2 is just around the corner, with support for several photography apps, as well as for FaceTime, Apple’s video-chatting standard currently available for new-generation iPhones and iPod touches.

A standalone FaceTime application is also available for Mac OS X, enabling Mac users to video chat for free over WiFi with their iPhone-wielding friends.