Yes, it is possible to use Launchpad Pro with iPad.
To connect your Launchpad Pro to an iPad you will need the Launchpad Pro mains power supply and an official Apple USB camera connection kit.
First, connect the Launchpad Pro power supply to the Launchpad Pro. Next, connect one end of the USB cable to the Launchpad Pro and the other end to the camera connection kit. Now, power on the Launchpad Pro.
Finally, you can connect the camera connection kit to the iPad and you'll then be able to use the Launchpad Pro with the iPad.
If you change the order of connection you may receive an error message on the iPad screen saying 'this accessory is not supported' or 'the attached accessory uses too much power'.