Ismoothproject has developed an Apple Script app which will allow your paid iPad-only apps to be transferred to iPhone and run on iPhone. The Apple Script app required for this is called iTelePad2Pod. It basically sends the .app file via SFTP to your iPhone or iPod touch which should have OpenSSH installed on it.
How To Run iPad Apps On iPhone and iPod touch
1. Download iTelePad2Pod Here.
2. Unzip iTelePad2Pod.zip
3. Move the iTelePad2Pod folder to the /Applications Folder on your Mac.
4. Go to the moved iTelePad2Pod folder (/Applications/iTelePad2Pod) and open the iTelePad2Pod application.(/Applications/iTelePad2Pod/iTelePad2Pod.app)
5. Follow instructions in the app.