I have one, but it is not for sale, but will give you a suggestion.
Take a piece of table cloth about 18 x 18, use a felt tip and make a few circles on it as a target with a bulls eye. Place some score numbers in the rings. This is your target and you lay it down on the table. Now make up some shot or take any shot from a book such as Carpelles Practicing Pool. You now practice that shot trying to land on the bulls eye or as close as you can. Do ten shot and keep track of you score. Use that as a guide to see how you improve.
As a game you and a opponent take turns shooting the same shot and you keep score. HIghest score wins. That is basically it.
Good luck on getting one.