My son is almost the same age. Getting any allowance or treats in our house is tied to doing chores- but here is the kicker: you must show a GOOD ATTITUDE as well as do the job for it to count. Pout or malinger and you will still have to do the chore, but you won't get paid for it and forget about going to that movie or having video game time, etc.
I used to get the groaning, putting it off, moaning too and I after losing my temper, pulling out my hair, etc. I finally just put my foot down. We had a talk with our son and told him that he is a member of the family and the household, just like we are. EVERYONE in the house has chores to do, and is included in that!
I made him list some of the chores he thought that his stepdad and I do. Then we added everything else he had left off, lol! I had him list the chores HE was asked to do- his list was pretty short compared to ours. I pointed out that chores like feeding the pets were because HE wanted pets and knew that taking care of them was part of the deal.
I asked him if his stepfather whined or complained when it was time to mow the lawn or take the dogs for one last walk late at night- or if he just DID it because it needed doing.
I also offered to trade some chores with him- like doing all the laundry, cleaning the toilets, etc. Compared to his chores, he said no!
You just have to be firm about it- and try not to complain about your own work, lol! We talked about how it is EASY to get into a habit of whining and complaining about things that must get done, but in the end, it just makes it unpleasant for everyone around you and doesn't help you get anything out of it. But the big incentive really does seem to be tying all rewards to 'showing willing' and having a good attitude to help out.
When he does do his chores without being reminded or any complaints, I always try to thank him for it and say " I really appreciate you bringing the garbage cans back to the garage before I got home so I didn't have to do it." I think a little acknowledgment of how everyone works together goes a long way. good luck!