It looks like the Kaossilator only has analog audio outputs. No MIDI. You will need to connect the iPad to a compatible audio interface, like this one:
Alesis iO Dock
Alesis is a highly respected established maker of audio gear, they make good stuff. But you might be able to find cheaper iPad audio interfaces elsewhere.
It is a dock, so you insert your iPad and then the iPad can use all of the dock's ports. Then you connect the Kaossilator to the dock by running cables from the Kaossilator outputs to the dock inputs, which then route the signal into the iPad. On the iPad, you will need to be running software that can record audio from an external source. One example of that would be Apple GarageBand, but there are probably many more apps that do that.
I have not used any of this software or gear. I simply bought the iKaossilator app for iPad/iPhone so I can do it all using only the iPad and it is soooo fun!
Have fun