As a customer I've used My Hammer a couple of times, and been quite impressed to be honest.
Put a job for a plumber recently as stopcock was seized and so was mains stopcock in the street. Someone quoted £30, thought blimey that's cheap. He came round, froze the pipe, cut out the old stop cock, replaced it with a shut off valve (the type you turn with a screwdriver), also gave my toddler son his LED hard hat light and sorted a leaky tap flexihose..... all for £40 including parts. Fella came from the other side of London too.
I'd been looking on there for a sparky before finding this forum.
I think it's free for both tradesmen and customers alike.