TechCrunchDec 21, 2016Brain-training app Peak sells majority stake to French publisher Hachetteverified_publisherTechCrunch - Mike ButcherSomething of a sleeper hit, the makers of Peak — a subscription-based service specifically designed to entertain a user while simultaneously exercising their cognitive skills — have sold a majority stake to French publisher Hachette Livre. Created by London-based app company Brainbow, Peak has been …