Download 3GP to iPad Converter and launch it, the interface like this:

Step 1: Add File - Click
to import video from the computer disk to the file list.
Step 2: Set output format - Choose the suitable output format from the profile drop-down list.

Step 3: Select output folder - Use default output folder or click
and set output folder as you will.
Step 4: Convert video - Click
to convert 3GP to iPad.
3GP to iPad Converter allows you to convert 3GP to MP4 which is supported by iPad and edit your output files if you want to.