Our son is still only turning 9 but we've decided to give him £1 per year of his age per month i.e. £9 per month, of which he must save more than half to avoid him spending it all on in-game purchases and sweets. This also helps him get into the saving habit and start to budget for higher value items.
The going rate for his friends who are this young seems to be around £1 per week, so it really is pocket money and not an allowance, but this comes with no chores attached.
By the time he's a teenager, he'll no doubt expect or need more, but some of the figures quoted in the feed above astound me, but then maybe that's a Wandsworth Common vs a Tooting/Streatham Common rate