The biggest problem right now has been the lack of a good mp3 player for the kids. Years ago we had the iPod. It was a perfect device. But Apple has discontinued that in favor of things that are basically iPhones.
There are a bunch of cheap Chinese-made mp3 players on Amazon, but they tend to have terrible navigation, sorting songs alphabetically, making it impossible to create playlists, inability to sort by genre, etc etc. I haven't found a good one (recommendations happily accepted).
So I gave the kids my old Android phone without a Sim card, and removed most of the apps, but of course they'll use the camera, and the browser... and I realized that this was just a slippery slope to that full-featured smart phone that I didn't want to get them yet.