Aldiko reader has to be considered as a worthwhile app for the simple reason that it transforms your smartphone or tablet into a eReader, while not costing you a penny.
Importantly, it supports the major eBook file types, ePub and PDF as well as Adobe's DRM encrypted books. The Aldiko would have gained serious credit if it allowed users to read previously bought books from stores such as Amazon/Kindle via the app, but no such luck - books bought via Amazon/Kindle stores can only be read on Kindle eReaders and apps.
Where the Aldiko really earns its money for us is with books that comes with no encryption, such as the classics that are out of copyright - Sherlock Holmes and Pride and Prejudice etc. Here is where Aldiko is great as it lets you pull your eBook from anywhere on your Android device and start reading straight away. It's even possible to open eBooks from cloud storage locations such as Dropbox.
Aldiko gives you full control of how you read your eBook. You can adjust pretty much any setting to suit your preference. Font type, font size, font colour, background colour, direction, spacing, brightness, margins, all sorts. If you can't find a comfortable reading layout with Aldiko, then you probably aren't going to be able to read books on your tablet or smartphone device with any app.
As well as giving you complete control over the aesthetics of the eBook you are reading, Aldiko also has a few handy features to help you along the way. First and foremost is saves your place in the book, but if your somehow lost your place, you can easily jump to where you were by a number one of the many search methods this app has; the two most useful are the ability to select a page nimbler and jump to it and also search for a word or words in any book - Aldiko will then find and display anytime the book mentions a certain word/phrase. I found this feature very helpful when re-finding my place in a book I was already reading on another device.
Two final features that are worth noting are; the nice display of books you are reading on your Android device; and the ability to buy eBooks from Aldiko's in-app store. All in all its a good app that free and worth a download.