From this timely post in the NY Times:
“The car is packed, the pets have sitters and the GPS is programmed. But have you properly prepped your children’s devices? While there are many apps that can keep a child busy, the best are those designed to promote active, engaged, meaningful and social learning, researchers say.
The NY Times details some recent apps for the job. Most work without a Wi-Fi tether, are free or very affordable and are rich in bite-size bits of interaction, making them easy to pass around the car. Platform and price information change frequently, so check your favorite app store for the latest information.