I'm with the pilots here. The FAs don't always know exactly when the flight passes through the 10,000 foot level. The announcement may come before or after.

So the simplest, easiest thing to do is simply stow the electronics when the announcement is made. At worse, you're going to have to do it a few minutes early, and you're usually on the ground within 20-30 minutes of the announcement anyway.

If you can't wait 20-30 minutes without electronics as the flight prepares for landing, you might want to invest your resources on developing teleportation.