Calibre 4.21 E-book Manager Released with Support for Kobo Nia, Improvements

It’s been almost two weeks since the release of Calibre 4.20 and the new version is here just in time for the launch of Kobo’s Nia e-reader, which targets newcomers and sells for only $99.99 USD. Calibre 4.21 is the first release of the popular e-book manager to add support for Kobo Nia. On top of Kobo Nia support, Calibre 4.21 adds support to vertically center e-book covers in the cover grid for those smaller than the available space, and implements a new checkbox that lets users easily apply virtual libraries in the Quickview panel.