Oyster's unlimited e-book service has been more of an exclusive club so far; you've had to read on an iPhone, and request an invitation just to get in. Both of those barriers are disappearing today. The company has just launched an iPad app that offers a more comfortable reading experience, with a dark backdrop optimized for night sessions. Customers also don't have to wait to get started -- Oyster is making its apps public, letting anyone sign up on a whim. There's no word of support for Android and other platforms at this stage, but iOS-bound readers can trial the service for free at the source link.