I loved having my children home for the summer. I never did any of the all day camps. We did an art class for a week or swimming lessons for two weeks.
Check into the summer activities for children in your community. Does the library have a children's story hour? Do any of the parks have any summer activities? Check the children's theater schedule, the zoo, the children's museum. Check into art classes and swimming lessons. Plan out your summer around the local activities for children.
When I was a stay at home mom we had a schedule. We did chores for about 1.5-2 hours in the morning--my kids got really good at folding wash cloths, picking up their toys, and putting their clean clothes away. About 9:30 or 10 a.m. we would go do something fun--play in the backyard, go swimming, go to the park, the zoo, the children's science museum. About 2 or 3 p.m. we would come home and they would take a nap while I finished up what I needed to do and made dinner. We did the free/cheap things Monday - Thursday. On Fridays we would blow it out. The kids would get up singing, "It's Friday, it's Friday." I would cook a big breakfast and we would go to Wave Pool, the Children's Theater, something that cost money. We even blew off naps on Fridays and they all went to bed early on Friday nights.
I used Friday as the motivator. Hey we want to go to the Wave Pool on Friday--put your dirty clothes in the laundry basket. It was the reward for being good all week. But, I never took Friday away when they were not well behaved. We would spend 15 less minutes at the park on Tuesday or 15 less minutes playing in the backyard on Wednesday, but I never took the Friday reward away. Good luck finding a schedule that works for you. The years that they are little slip by so fast. Enjoy your summers!