The perils of releasing an update to an app that users dislike are well known: one-star reviews ahoy! Personal radio service Pandora is the latest company to suffer, with its versions 3.2 and 3.2.1 updates for iPhone. BTIG analyst Richard Greenfield has written a research note highlighting user anger at the app’s tweaked UI and “excessive display advertising”, with one-star reviews piling up for the update. Pandora can’t pooh-pooh the issue either: 70% of its listening comes on mobile devices, with iPhone a big chunk of that. With Spotify recently launching a competing Radio feature in its own smartphone apps, Pandora needs to retain its users’ loyalty.