The credit of the work goes to Comex, the guy behind Spirit and JailbreakMe tools for iOS devices. It works seamlessly with iPhone 4 iOS 4.0.1, iOS 4.0 only and can confirm that it works. You can see it in the video embedded below.
Howto Install Flash on iPhone 4, iPhone 3GS
Update: Easy Install Flash on iPhone4, iPhone 3GS
- Open Cydia > Manage > Sources
- Edit source and add http://repo.benm.at
- Search Frash and install it.
Step by step Flash installation
Step 1: Connect your iPhone with your computer. Make sure iTunes is not running.
Step 2: Using any SSH client, SSH into your iPhone using root/alpine and Navigate to /var/root/Media directory and create a folder named “Cydia”. Inside this Cydia folder, create another folder and name it “AutoInstall” and copy the Frash-0.02.deb file.
Step 3: Restart your iPhone and enjoy Flash on your Safari browser by click on the “Flash” text to play the Flash content.