What's the best cell phone for kids?
Honestly, the best cell phone for kids is one they use responsibly and respectfully, in accordance with the guidelines you've discussed. Any phone could fit this description. But, kids being kids -- and the rapid pace of technology -- make this ideal hard to achieve. That's where devices specifically designed for kids can make boundary-setting easier, because they have limited options.
For younger kids, consider bare-bones phones with only the features they need to stay in touch with you. As kids get older, they'll be interested in fuller-featured phones with bells and whistles. A good compromise is a device you can customize to suit everyone's needs and wants. If you're going to give kids a smartphone, turn off some of the advanced features (downloading apps, for example) until they've demonstrated responsible ownership.
Here are some ideas for kids' cell phones:
Young kids: Look for phones with very simple controls, big buttons, and extremely limited features. Phones that only make calls to a short list of contacts and that have no games, no Web access, and no camera are good choices. Consider the Sprint WeGo, the Firefly, or the FiliP 2, a watch that makes calls to an abbreviated contact list and receives -- but can't send -- texts.
Tweens: Phones that look grown-up but offer limited features or that come with a service that allows you to customize options are good choices for older kids. Take a look at the Kurio phone, the Kajeet service, the Just5, or the TracFone, which can't download apps.
Does your kid have a special kid phone?