Jake's 1st text

I picked up my cell phone this morning, and looking at it, I noticed a text message.  Well, it was from Jake.  He had done his own text on my phone to a friend of his.  It was so cute.  He wrote, "Hi Avary.  how are you doing? P.s this is Jake"  He's only 9!!  At what age are you supposed to let a kid get a cell phone?  We held out as long as I thought possible with Ethan, and we made it until he was 14.