Apple seeded the first beta of iOS 10.3 yesterday right after they released iOS 10.2.1 to the public. The field test app is a “hidden app” within iOS which can be accessed from the phone app by dialing *3001#12345#* on the dial pad.
The field test app can be used to quickly find out a lot of information about your cellular connection like the LTE Band you’re connected to, the bandwidth available etc.. Apple hasn’t updated the app for a very long time fence falling behind the curve and not showing a lot of the information the new iPhone(s) now support like carrier aggregation.
Field test mode on an Intel iPhone 7 with iOS 10.3. pic.twitter.com/EdqFxvE7Nn
— Peter Clarke (@PedroClarke1) January 24, 2017
The new screenshots show that the app is now updated for the larger screens, shows a lot more information about different “carriers” of LTE bands and most importantly showing the current carrier aggregation status.
Currently the new app is only on the Intel version of the iPhone 7s’ but, it should roll out to other devices in future betas.