This deal is usually £10, but sometimes goes down to £9
You get 4GB data, unlimited texts and minutes, this would be a great plan for kids and family, plus the referral system would be good to get the whole family on-board on this deal:
The link for referrals: https://www.three.co.uk/refer-a-friend
I think you can refer up to 5 people, so up to to £125 for yourself and £25 for each person you refer.
Things to take into note: No Personal Hotspot Allowance and no Feel At Home, the contract is 12 months.
Like I said this would be great for the family or people who don't use much data.