I gave my daughter her first phone at 6! It wasn't an iPhone! But it did what I wanted it to do, ring and text me. As a single dad, I had to work, and after school she would have to go to other children's houses after school. Our neighbours usually took her but often enough, I had to make other arrangements. So I would text her asking her if she was ok with going with such and such a person today. And my daughter was constantly (still does) forgetting her gear for practice. So i'd often get a text asking me to drop off gear bags and sometimes lunch or money. And on a couple of occassions the parents I had asked to collecct her had forgotten to pick her up or mixed up the dates! Once, she forgot her phone on one of those days. She was left on her own outside the sports field for an hour (6 o'clock, on a winters evening, it was dark) until I realised. She didn't want to leave the field because she was afraid and she didn't want me to show up and she not be there. She was 9 years old! That phone helped us so much! She's almost 13 now, and she has a smartphone. I must say, she's great. In all fairness, her bill is never more than €20, compared to my bill of €200+. She doesn't text much. Most of her bill is internet usage. She goes on youtube, downloads music, plays games and all that crap! And if you were to go through her logs, 90% of the calls and texts are to me!
EDIT - Did I mention it contains a GPS tracker? I rarely even use it. But it 's a handy device!