The best way to give a pill to a cat is to hide it in a ball of favourite food, like cheese or meat, or if he prefers the pill pockets treats found in pet shops. Using this method you need to be very attentive if he swallows the tablet as cats can be very smart in hiding the tablets.
The next good method is the pill applicator which you already tested and did not proved to help you.
You can also break the pill in very small pieces and mix it with a small quantity of favorite food, but in this case you need to make sure he eats it all. Some cats depending on the pills will refuse to eat. Also please bare in mind that some medicines are given on an empty stomach.
And then there are alternative medicines which are injectables, paste, topical administration, but the use of these is restricted by the kind or treatments your pet is on.