Girl, you’re so old school with your talk about cell phones… Step into the 21st century and show him you care by having a GPS transmitter surgically implanted in him! 
Just general observations, but we didn’t track our kids in any ways like that. We always insisted on knowing where they were going. Still do, tho they are aged 15-19. Like to a friend’s house, we would want to know the name of the friend - and if a parent would be home. And if they changed their mind and went somewhere else, they were to call us and let us know. And they knew that if we ever tried to get in touch with them and they weren’t where they said they’d be, they’d catch holy hell.
But if they wanted to have a friend come over and go bike riding, for a walk, or to the park for hours on end, we’d say “Go ahead” and just discuss when they needed to be back by. Didn’t require that they bring a cellphone with them.
I guess they could have been going to crackhouses instead of the park, but we chose not to worry about that and to trust our kids. And we told the kids any specific boundaries given their age at the time (i.e. don’t cross a certain busy street.) I mean, if your kid wants to lie to you he will. We preferred instead to rely on our consistent messages to help our kids not make overly stupid and dangerous decisions. And I feel allowing your kids ever increasing freedom and responsibility is key in raising decent adults.
As far as I can tell, all of our kids were pretty honest and responsible along these lines. Maybe I’m majorly gullible, but I don’t think so.
My kids don’t appear to have any real interest in cell phones, but they seem to be the exception among their peers. There are many a time during which a cellphone would be useful - say if they are at a school function and need to tell you when or where to pick them up. We only have one cell as a family, and if one of the kids really needs/wants one, they can take the family cell.
If he wants a cell, he will be thrilled with the gift. If not, he might be ticked at having a part of his present-allocation go to that.
One shortcoming with the cellphone is that it tells you if your kid is alive, but doesn’t tell you where he is. Now you could have him take a picture of his immediate surroundings… Go with the GPS chip!
Where are you at DB? What exactly are you worried is going to happen to him?
At 10 I’d say it is a good thing to have him walk/bike over to his friend’s house by himself. And depending on where you live, you can always say “Ride your bikes anywhere within this area.”
I know how common it is to worry that disaster will strike your loved ones. But my wife and I made the conscious choice some while back to not lead our lives as tho the worst possible thing was going to happen at any particular moment.