When purchasing gadgets actually there is no rule to follow but you should have commonsense that you might want to consider. There are many disadvantages if kids are so into gadgets and the first one is the kids don’t know how to communicate with other kids, and how to mingle with them.
So if you are going to buy a gadget for your kid. You have to consider on researching the current affects on children. Does gadget can teach your child something, you also have think of does your kid really need or your kids only want. The maturity of the kid must also have to consider.
When the gadget is there already, you have to set limit of how many hours your kid should spent on playing gadget. Your kid needs to explore, needs to play, they have to socialize and make friends with the neighbors.
Parents should also be vigilant of what your kids are exploring on the web or the game that they are playing. You have to check them every day, so their minds will not be corrupted by this so called technology.
In short be there always when they start opening their gadgets.