Ask HN: Best distraction-free phone platform?

There's been a spate of articles recently about the negative and addictive effects of social media and smartphone addiction. I'd like to move to a phone that never lets me use the 'unrestricted' infinite-scroll Internet (i.e. no Facebook, Google, Instagram, web browser) but, ideally, allows a small number of limited-content apps with no infinite scroll (WhatsApp for communicating without SMS charges, perhaps Facebook Messenger, Google Maps etc), and, for bonus points, has a good camera. Perhaps a custom low-addition build of Android, or some way of completely removing the temptation of Safari on iOS?

Thoughts, or alternative ideas for dealing with this? I've already downloaded Freedom but am looking for something more permanent that doesn't involve any self-control. Alternatively, any suggestions for good dumb-phones that will still work on 3/4G-only networks?