This is an internal build of iOS 9.0, originally discovered on an iPhone 6 PVT, which runs SwitchBoard. A dump of its filesystem weighs in at around 4.63 gigabytes.
This firmware has the kernel version
Darwin Kernel Version 15.0.0: Tue May 3 12:15:09 PDT 2016; root:xnu_development-3247.1.88.0.2~20/DEVELOPMENT_ARM64_T7000.
Interestingly, this build contains Alternate Reliability in addition to its regular counterpart. Operator also seems to have a redesign as well. The Phone app from iOS seems to be present in this build, strangely.
Upon booting into SwitchBoard.app, you’ll find the following applications:
- Duet Viewer (hidden)
- MIDINetSetup (hidden)
- MobilePhone (hidden)
- Operator (hidden)
- Alternate Reliability
- Sightglass (In /AppleInternal/Diags/Sightglass/Sightglass.app)