Step 1
Launch Cydia, click on Manage, Sources, then Edit. Until BigBoss adds the app to the main repository, you'll need to add the following repo:
http://thebigboss.org/semitether

Step 2
Select thebigboss.org repo.

Step 3
Select and install the app SemiTether.


This will give you the ability to reboot with limited functionality in an emergency. Here is a summary of what you can and cannot do during the semitethered boot:
- Can use phone, sms (text messages)
- Can use every other stock app on iphone.
- Cannot use mobile safari
- Can use other appstore web browsers such as atomic web browser
- Cannot use mail app. You could install a gmail app from appstore or such instead.
- You cannot use any jailbreak tweak, app, cydia until you boot tethered.
- While in the semitether booted state, you should not add a jailbreak ios5 notification such as sbsettings to notifications during this state or your device will be stuck in a respring loop until you get home to “boot tethered”.
