We have bought a second hand kindle for our 6yo to entertain her during the long drive to our French campsite this summer. We also have another rather elderly kindle, which will be passed on to our 4yo for the drive and is already loaded with Teach Your Monster To Read and a variety of Cbeebies apps. The 6yo has outgrown these apps, and 4yo enjoys them but could do with a bit more variety.
Can anyone recommend some good apps please? Ideally free or cheap, work offline (so we don't have to keep tethering it and using all our data!), and at least vaguely educational. 6yo would particularly benefit from something maths-based, and 4yo is just starting to read and keen to improve, so games in these categories would be great, but also a mixture of games/stories etc.