Step 1: Load DVD files
Click "Open DVD" button, select a DVD (or DVD Folder, IFO file) in the dialog box that opens, and load it. The Loaded DVD's information, such as chapter, title, etc., will be shown in the file list.

Step 2: Choose output format
Select one or more files in the list, click "Profile" drop-down button, select an output format for selected files in the drop down list that opens.

Step 3: Rip DVD to iPhone
Check the needed file to extract in the file list, click "Convert" button on the main interface, to start extracting the file. You can view the progress of the extracting process from the progress bar at the bottom of the window.
Step 4: Watch DVD on iPhone
Connect iPhone to computer via iTunes and open iTunes. Click "File -> Add File to library" to add the converted videos to iTunes. Then sync the video to iPhone and watch DVD on iPhone freely!

Read Guide: How to Transfer DVD to iPhone?