Gabb seems to be the closest, but even that has a "virtual pet" type game built in that gamifies certain things.
I've also done an android phone with an MDM in kiosk mode. None of those let you limit who is contacted though, so it ends up being more like a classic dumb phone in that you can't browse the web, but can dial whomever you want. Just make sure that you disable the Google SMS app and use a stripped down one (I used simple-sms).
I've also done an android phone with an MDM in kiosk mode. None of those let you limit who is contacted though, so it ends up being more like a classic dumb phone in that you can't browse the web, but can dial whomever you want. Just make sure that you disable the Google SMS app and use a stripped down one (I used simple-sms).