my 2 pennies worth advise, take your child to the nearest school to where you live - as for the academic part, my searching did not yield any results - in most schools the kid is always introduced to some form of academics, be it coloring or just fooling around with a crayon or pencil.
most of the institutions that offer the play group also have the upper levels and thus the kids when interacting will always see other kids with pencils or markers and they will also want the same. I see no harm in that, especially considering class 1 entrance exams have turned into mini KCPE,s and KCSE's and your kid needs to be properly drilled to pass one.