One of the problems with frictionless Facebook sharing of music is that for most people, only a small proportion of their friends will be a firm match for musical tastes. iPhone and Android app EQuala is offering one solution: a ‘Friends EQualizer’ that serves up personalised radio streams based on what Facebook friends have been playing – but with a slider system to ensure the people you trust are higher in the mix. “By creating a ‘Music DNA’ for each user, EQuala presents the ‘% match’, or music similarity, between you and any other user,” explains its website. The app is US-only for now, presumably for licensing reasons. It’s a clever idea, albeit one that you can imagine being a feature for the existing on-demand services, rather than necessarily a standalone service.