Honestly, I would focus on "preparing" him for k next year with experiences rather than flash cards. It doesn't sound like he enjoys them anyways and learning should be fun not a chore, especially at this age. I would say try some classes, outings, etc. to create learning opportunities that are also social experiences. There is often alot you can do at pretty low cost. Parks are great for collecting nature specimens and learning about them. The zoo of course is always a great option, museums, etc. Follow his interests. Teach him to love learning. That will take him much farther than early entrance to kinder would, imo.
