Make sure you have added installer.iclarified.com installer source. You can find instructions on how to do this here.
Press to launch Installer from your SpringBoard.
Press to select the Install tab at the bottom of the screen.
Press to select iClarified from the list of Categories.
Press to select Pysl from the list of Packages.
Press the Install button at the top right hand corner.
Press the large red Install button that appears.
A notice will appear asking you to Confirm installation. Press the large OK button.
Another notice will appear asking you to reboot your iPhone once installation is complete.
Once installation is complete you will be returned to the Categories menu. Press the Home button to return to your SpringBoard. Notice the new Pysl icon.
Now hold the Sleep/Wake button for three seconds until you see the Power slider. Slide this to right to turn off your iPhone. Then push the Sleep/Wake button again to turn your phone back on.
Press the Pysl icon to launch the application.
Press Settings to open the Settings Menu.
Enter a new password to restrict access to this area then press the Save New Password button.
Press the Password Changed button that appears.
Press the Back button at the top left of the screen.
Press Blacklist from the Welcome screen.
Press the Add button at the top right hand corner.
Press to Add number from contact
Select an address book entry from your Contact List.
Step Twenty One
Press to select a Contact's Phone Number to use as a filter.
Step Twenty Two
You will be returned to the Add To Black List screen. Here we have the options to enable three switches.
SMS STOP: hide SMS and store in SMS History
SMS DELETE: hide SMS and delete it "on the fly" (without saving in SMS History..no trace)
CALL STOP: hide CALL and register call in CALL History (not available yet)
I have enabled SMS STOP to hide SMS for this person. Then press the Add contact to list.
Step Twenty Three
You will then be returned to the Blacklist. Press the Back button at the top left.
Step Twenty Four
Switch the Pysl Enable to the ON Position.
Step Twenty Five
Now to test Pysl, send an SMS to the person you just added to your Blacklist. Then reopen Pysl. Notice you are asked for your password!
Step Twenty Six
Select SMS History from the Welcome Screen.
You will now find that your SMS is displayed here but it is not displayed in the iPhones MobileSMS.app!