This is a comprehensive list of all the permissions and how we use them:

WRITE_SETTINGS

Used to write the brightness, volume, airplane mode, auto rotation, screen timeout, and unlock pattern on/off in the System Settings when the respective toggle is pressed

ACCESS_WIFI_STATE

Used to detect whether the Wifi is on or off and displayed on the indicator light under the toggle button

CHANGE_WIFI_STATE

Used to change the Wifi on/off state when the toggle button is pressed

WAKE_LOCK

Used for Wifi On/Off for devices running Android 1.6

BLUETOOTH

Used to detect whether the Bluetooth is on or off and displayed on the indicator light under the toggle button

BLUETOOTH_ADMIN

Used to change the Bluetooth on/off state when the toggle button is pressed

INTERNET

Used for displaying ads and for the promo code page

ACCESS_NETWORK_STATE

Used to check Internet connectivity in the Registration process

READ_SYNC_SETTINGS

Used for detecting autosync setting change and on/off state

WRITE_SYNC_SETTINGS

Used for changing the sync settings to on/off

GET_ACCOUNTS

Used in conjunction with READ_SYNC_SETTINGS to detect whether background data is enabled.

WRITE_APN_SETTINGS

Used to change the Access Point Names by adding an identifier at the end, making the one you are currently connected on no longer available.