Perhaps not financially viable in some areas, where schools offer breakfast care for as little as £2 a session, or where families can arrange a free option like grandparents or reciprocal arrangements with friends. And unlike preschoolers of course, some parents are happy for their school children to be alone at home for short periods rather than pay for childcare - as young as Yr 6, I've found.
Providing yummy meals and homework help is a must for some families, to make it worthwhile alternative to after-school clubs.
Getting to know the children is important, they are old enough to get involved in planning if they want to - use their hobbies and interests as a starting point for your planning.
Board & card games are popular here, as are group activities like charades and party games like the Queens Keys. Projects like make a comic/newspaper, devising plays, talent contests, fashion shows. Role play, crafts, construction.
Use the internet or library books to let the children choose craft projects, recipes for cooking, science experiments etc. Half the fun is in the planning sometimes.