We loved it! Stayed there last year at the end of August, beginning of September 2015. Here's my review:
We spent a week at Red Apple & found it just about perfection. Check-in was pleasant, quick & the fact that they don't honor credit cards & only take checks or cash was no problem for us. A very quiet campground, in spite of the number of people there. The full hookups were well located & functional. The wi-fi was a bit sporadic at times. If staying in late August/early September, it would be beneficial to request a site away from the oak trees which drop their acorns loudly! Many seasonals, but those sites were well kept & nicely landscaped, as was the entire campground. Everyone was very friendly, staff & visitors alike. The bathhouse was spotless, as was the laundry room where it appeared that the front loading washers & efficient dryers were brand new. There was a small enclosure where our dog could be off leash, complete with dog toys. Also, it was fun to walk with our dog around the pretty campground, visiting with other campers/seasonals. We took advantage of the lobster delivery right to our picnic table on two occasions. Steamed, ready to eat, absolutely delicious & a lot less expensive than what one would pay in a restaurant. Red Apple is well located to explore Kennebunkport, Wells, Cape Neddick, Ogunquit & York. And we drove a bit north to Portland one day (1/2 hour trip) & took the dog friendly Casco Bay Mailboat tour. A highly recommended spot!