How to:

1) The first thing you need is to download the archive from here
2) Extract all that stuff from the archive.
3) Go to the folder BadaAppsSignature, you will see a certificate called BadaCertificate.cer
Transfer this cert file on your phones memory card.
4) On the phone open My Files and browse to the certificate we you just transferred in previous step and click on it to install this certificate. Click yes on the prompt.

Now time to install real game or apps:

5) Take any unmodified game/app, extract it somewhere say for example on desktop.
6) Now run BadaAppsSignature.
7) Click on the button highlighted in red.

8) Now give path of exe file by browsing to the .exe file of the app/game you are installing (.exe file found in the bin folder of the game/app)
9) Click to open, the window closes. See BadaAppsSignature and press the red button:
10) Go to the folder with the game/app, after successful completing the previous step you will find two files in the main folder of the app/game:
11) Simplilly delete the Signature.xml
12) Now rename the Signature(2).xml to Signature.xml.
13) Go to the folder Info, you will find a file Appinfo.sys, open it with notepad.
14) In the notebook you will see something like this:
15) Copy the AppId just like highlighted in the red color in above image.
16) Rename the main folder of the game/app.
17) Connect phone to PC in Mass Storage mode.
18) Copy the folder you just renamed and paste it on the following path:
Memory Card => Others => __@@ bada_applications @@__
19) On your phone, change the installation location from the phone to Memory card. (Every time to have to do this coz as you connect your phone in mass storage mode installation location changes automatically to phone memory)
20) After pasting the app/game folder to the above mentioned path disconnect your phone.
21) Again reconnect your phone normally to PC i.e. Kies mode
22) As BadaAppsSignature is running, Go to the second tab of the program, enter the AppId you copied in 15th step in the box below, click on the dropdown and select the item and click the button (highlighted in red in below image)
And finally you have successfully installed the game/app.
Happy Spoofing guys….