How to Install A deb file ?

1st Method:
STEP 1: Download the .deb file you want (example : LockInfo)
STEP 2: Start Cydia, go to "Search", type "Mobile Terminal" and install it

STEP 3: Repeat step 2 for "OpenSSH"

STEP 4: Start "MobileTerminal"

STEP 5: Type the following commands :

su (press return)
alpine (press return) /!\ You won't see the typed password then don't worry /!\
dpkg -i nameofpackage.deb (press return, replace nameofpackage with LockInfo for the example)

STEP 6: Reboot
enjoy the deb file is now installed on your mobile
2nd Method:
STEP 1: Connect your iPhone with SHH Software
STEP 2: Create the folder Cydia/AutoInstall into var/root/Media/
STEP 3: Reboot your iPhone
Once Done directly place all the deb file in this created folder and restart twice (two times) and bingo its installed this method is used by cyder also