The release of the Google (Asus) Nexus 7 in late 2012 launched a very impressive 7 inch tablet device running Android onto an eager marketplace. The question we asked at the time is “can Android tablet devices replace Kindles, Nooks and iPADs in the ever changing world of ebook readers?”. We said we thought so, at least from a technical point of view, and assuming a really good PDF viewer is available (see further, below). Here is our review at time – the evidence since then seems to support these views, with similar products being launched by other providers such as Samsung, and new size versions from Google (5inch, 10inch and a rumored 9inch forthcoming).
The image below, from the Google Nexus website (see link below) provides a first look at this question – in this case illustrating a conventional ePUB ebook. The Kindle reader for Android looks much the same, although when rotated seems to insist on showing two columns rather than one, which is not ideal for reading.
In principle this looks fine – firstly, it has a really good hi-res screen (1280×800 pixels, or 216dpi (2012 version – latest versions are an extraordinary 323dpi), which is far far better than typical computer screens – most have less than 100dpi). Second, the screen auto-rotates so text can be displayed much more clearly if an entire page width is used as the zoom setting (“fit width” in PDF parlance). However, to do this you first have to enable auto-rotation, as Google for some reason have it disabled when you first get the device. Also, the term 7 inch is a bit misleading – the available diagonal screen size when reading a document is roughly 6.5inches, and in landscape view this equates to just over 5.5 inches (15cms) or only 3.5inches (9.5cms) in the standard portrait view.
The image above shows re-flowable text, whereas PDFs provide formatting and fixed layouts. If the layout includes margins, which is generally the case with PDF documents, then this white space limits the available width, as shown in the test image below:
Of course, this image is actually larger than the physical screen, but the results are nonetheless very readable (the resolution difference between the PC and the Nexus accounts for this).
Markup and annotation are features that some users require, and the image below shows this in an implementation which will be similar to the one used by our Javelin reader for Android: