Cosequin is a glucosamine supplement for cats that is widely recommended by vets. My elderly cat has developed some joint issues and I started him on this about a year ago. Although it hasn't worked miracles by any means, I can definitely see an improvement in his movements. He still has trouble going up and down steps and jumping on the bed, but he is able to do these movements without too much discomfort now. On rainy days however, he doesn't move much. I plan to keep him on this for the rest of his life because I know that even though there may not have been much improvement, there also has not been much advancement of his arthritis. It is also really simple to give him the medication. I simply pull apart the capsule and sprinkle the powder into his food. He does not notice it at all. 

Cosequin is available at most pet stores and online. The price varies quite a bit, from $14-$25, depending on where you get it. Definitely shot around for this!