The T-Mobile family plan has worked great for us. T-Mobile's plans are nice for us because:
- The third, fourth, and fifth lines are only $10 / month.
- When the paid-for data is exhausted, the plans automatically switch over to unlimited free low-speed data for the rest of the month.
- Streaming music doesn't count against the data caps.
- Free phone calls, texts, and low-speed data in Canada and Taiwan. (It was great using Google Maps to get around Vancouver. I was using many short cuts that I didn't know about when I was navigating using paper maps.)
- For the last 3 months of 2015 T-Mobile had a special where they gave everyone unlimited high-speed data for free.
I ended up getting used iPhone 5s's for all my kids. I had the kids pick their own otterbox commuter cases.
My son was initially frustrated at having to give up his rooted and customized Android phone for the smaller, less customizable iPhone. He's grown used to it, and likes it now. Everyone loves the fingerprint unlocking feature of the 5s.
I have the phones set up with restrictions, so that the kids can't install their own apps. I also confiscate-and-recharge their phones and laptops each night. This is fairly foolproof, and gives the kids 8 hours a day to sleep without electronic distractions.
I bought an Anker 6-port USB charger for my bedside table. I use it to recharge everyone's phones while keeping an eye on them. I have the phones on "Do Not Disturb" mode, so they don't bother me over night.
The "Find my Friends" app has proved helpful for keeping track of where everyone is, especially for things like picking kids up at school and at bus stops.
We now have 5 laptops: four 13" Macbook Airs and one 13" Macbook Pro. They work great and last a long time. They are mostly used for web surfing, YouTube and Minecraft.
We have had problems with headphones -- the kids are rough on headphone cables. They've already gone through one set of headphones each. Currently we're using Beats headphones due to them being relatively cheap on sale and/or included in Apple Educational bundles. They look stylish and work OK. Apple has a fairly good warranty repair process for their Beats headphones.