Filesystem:/Applications/CheckerBoard.app

Summary
This (hidden) application is usually accessed by powering off the device, then after plugging in a charger, start holding down the volume up button and home button. It is present on all iOS 10.3 devices.

It looks to be sending data to https://idiagnostics.apple.com, however due to certificate pinning, the data being sent is unknown. It is known to connect to AST2, an internal diagnostics web app, for diagnostics.

Other Information

 * It may be worth noting that the time displayed at the top-left (in the case of an iDeice without Airplane Mode) of the screen is Pacific Standard Time, regardless of user preferences.

Localization strings
Extracting its English localization strings yields these:  /* ARE_YOU_SURE */ Are you sure you want to exit Diagnostics?

/* CANCEL */ Cancel

/* CHOOSE_OTHER_FOOTER */ Choose Another Network

/* CHOOSE_WIFI_HEADER */ Choose a Wi‑Fi Network

/* CHOOSE_WLAN_HEADER */ Choose a WLAN Network

/* COULD_NOT_FIND_NETWORK_TITLE */ Could not find the network “%@”

/* DIAGNOSTICS */ Diagnostics

/* DIAGNOSTICS_DESCRIPTION */ Diagnostics allow Apple to identify potential hardware and software issues with this device.

/* DISMISS */ Dismiss

/* DONE */ Done

/* EMERGENCY_CALL */ Emergency Call

/* ENCRYPTED_NETWORK_PROMPT */ Enter the password for “%@”

/* ENCRYPTED_NETWORK_TITLE */ Enter Password

/* EXIT_DIAGNOSTICS */ Exit Diagnostics

/* FAILED_NETWORK_PROMPT */ Failed to join “%@”

/* INCORRECT_PASSWORD_TITLE */ Incorrect password for “%@”

/* JOIN */ Join

/* JOINED_NETWORK_PROMPT */ Joined network “%@”

/* JOINING_NETWORK_PROMPT */ Joining “%@”…

/* NEXT */ Next

/* NONE */ None

/* NO_NETWORK_CONNECTION_MESSAGE_WIFI */ The Wi‑Fi network you selected is not providing an Internet connection. Change your settings or choose a different network.

/* NO_NETWORK_CONNECTION_MESSAGE_WLAN */ The WLAN network you selected is not providing an Internet connection. Change your settings or choose a different network.

/* NO_NETWORK_CONNECTION_TITLE */ No Network Connection

/* OK */ OK

/* OTHER_NETWORK_NAME */ Name

/* OTHER_NETWORK_PLACEHOLDER */ Network Name

/* OTHER_NETWORK_PROMPT */ Enter network information

/* OTHER_NETWORK_TITLE */ Other Network

/* PASSWORD */ Password

/* SECURITY */ Security

/* SERIAL_NUMBER */ Serial Number

/* SHUT_DOWN */ Shut Down

/* START_DIAGNOSTICS */ Start Diagnostics

/* TEMPERATURE */ Temperature

/* THERMAL_ALERT_STRING_IPAD */ iPad needs to cool down before you can use it.

/* THERMAL_ALERT_STRING_IPHONE */ iPhone needs to cool down before you can use it.

/* THERMAL_ALERT_STRING_IPOD */ iPod needs to cool down before you can use it.

/* TRY_AGAIN_MESSAGE */ Please try again later.

/* UNABLE_TO_JOIN_NETWORK_TITLE */ Unable to join the network “%@”

/* UNABLE_TO_JOIN_TITLE */ Unable to join “%@”

/* WEP */ WEP

/* WIFI_SETTINGS */ Wi‑Fi Settings

/* WLAN_SETTINGS */ WLAN Settings

/* WPA */ WPA

/* WPA2 */ WPA2

/* WPA2_ENTERPRISE */ WPA2 Enterprise

/* WPA_ENTERPRISE */ WPA Enterprise

Folders

 * _CodeSignature/
 * ar.lproj/
 * ca.lproj/
 * cs.lproj/
 * da.lproj/
 * de.lproj/
 * el.lproj/
 * en.lproj/
 * en_AU.lproj/
 * en_GB.lproj/
 * es.lproj/
 * es_419.lproj/
 * fi.lproj/
 * fr.lproj/
 * fr_CA.lproj/
 * he.lproj/
 * hi.lproj/
 * hr.lproj/
 * hu.lproj/
 * id.lproj/
 * it.lproj/
 * ja.lproj/
 * ko.lproj/
 * ms.lproj/
 * nl.lproj/
 * no.lproj/
 * pl.lproj/
 * pt.lproj/
 * pt_PT.lproj/
 * ro.lproj/
 * ru.lproj/
 * sk.lproj/
 * sv.lproj/
 * th.lproj/
 * tr.lproj/
 * uk.lproj/
 * vi.lproj/
 * zh_CN.lproj/
 * zh_HK.lproj/
 * zh_TW.lproj/

Files

 * Assets.car
 * CheckerBoard
 * Entitlements.plist
 * Info.plist
 * PkgInfo