Touchpad controller for ps4
Good news - Yes you can.
The PlayStation app (available on the play store or app store) allows you to sync a smartphone or tablet to your PlayStation 4 and use that as a controller. The process is fairly straight forward.
Once you open your app, at the bottom of your screen you should be able to find a "Connect to PlayStation" option. If you are connected to the same wifi network with the PlayStation and the tablet/smart phone, the PS4 should appear on the list
Next you will need to open the Settings in your PlayStation dashboard, and open the "PlayStation App Connection Settings". This will give you a code to into your tablet/phone, and you should be all good!
This video should provide some more detail for you:
This goes into a bit more detail about the functionality of it: