I have a Yr8 and a Yr9, but not much has changed since Yr7
Lunches - school has compulsory school lunches which are invoiced termly (set cost) on the fee bill - so no issues there. Any snacks etc come out of their pocket money.
Pocket money - £20pm in start of yr 7, goes up £5 per month on each birthday. They have a bank account and bank card, and manage their own money, but I have weekly balance texts sent to me (NatWest). This covers snacks/socialising etc. We still pay for cards/presents for friends parties, clubs, phone and gym membership. They get extra money for holidays (usually an extra £50 in the long summer holiday, and an extra £25 for shorter holidays) to reflect they need more money for activities then. They also get fairly generous birthday / Xmas money from family and friends, but we hold that in a separate account and transfer as needed so they don't blow it all at once! They don't have to do chores for their pocket money, but are absolutely expected to keep their rooms broadly tidy and help our around the house as needed.
They walk to school and back (2 miles each way). They don't tend to socialise much in the week beyond sports/clubs due to time restrictions. They do socialise pretty much every weekend - allowed to walk to our small town to go to the shops/for a Costa/for a meal, or walk to the leisure centre for swim or gym. Cinema/Bowling etc are in a town much further away, so we'd generally take them and pick them up. Eldest has gone on the train with friends to bigger town, but that's rare, and is subject to restrictions (tracker on phone switched on-ring we when arrived, ring when catching the train home etc).
Phone contract is £7.50 p/m and paid by us. Plenty of mins and texts,but never enough data for them! (around 1G)
Allowed Instagram, but I have logins and regularly check in. DD also has Snapchat. Increasingly since yr 7 social events have be organised via social media, and by Yr 9 it's pretty much the only way that anything is organised, including birthday parties etc. Children who don't have access to social media will miss out significantly on social events. Might just be OK in Yr7 without it at a push. IMO it's better to teach them to use it responsibly (and set limits such as needing their password etc) than to not allow it. Most children that are banned from it just have accounts that they set up secretly and hide from their parents, and are then are using it completely unmonitored. It's a big thing, and hugely hard to police, but better to allow it and manage it than to ban it IMO.
Phones and ipads downstairs overnight. Internet switches off at 8.30 pm and they are in bed 9/9.30 ish during the week, probably around 10 at weekends. (in Yr 7 internet was off at 8, bed 8.30/9).
They manage their own homework, but I have a zero tolerance policy on it not being done, or not being done to their best capabilities. DD is good at this, but DS does need the odd reminder. The school is strict on homework and good at communication, so we absolutely know if there are any problems with homework.
DH and I are both of the work hard, play hard mentality and we encourage that in our children too.