Your smartphone is a window into the world of unlimited e-books, and you can browse, buy and read digital books directly from your device whenever and wherever you want.

Just like real libraries need people to sort and arrange books, you will also need an application that keeps your e-books in one place and helps you find what you need, said David Neld in a report published in the American magazine Poplar Science.

Amazon Kindle
The word "Kindle" was a synonym for e-reading thanks to Amazon's popular e-ink devices.

The company has developed the free Kindle app for Android devices, phones and tablets running iOS.

The main feature that distinguishes Kindle from other reading applications is its ability to access the Amazon e-book library, starting with free and non-copyrighted classics such as The Great Gatsby.

The app also provides access to recently released books, most of which come with a free sample in case you want to read them. Audio books are available through a standalone subscription-based platform and an app called Audibel run by Amazon.

Kindle app with access to Amazon's huge eBooks library (US Press)

IBook
With this app, you can buy new ebooks and audiobooks and browse your own library.Ibox proposes new books for you to read based on what you've read in the past.It provides you with a list of best-selling books.This app includes another useful feature: Like to read and that you can create from the library.

For reading, you can choose from eight font types, multiple text sizes, and four different color schemes.The app also provides a scrolling view mode so that e-books become one long page of scrolling text instead of separate pages you browse.

But the bookstore is only available on iPhones, iPads and Macs.

E-apps allow you to buy new eBooks and audiobooks and browse your own library (Getty Images)

Google Play Books
The Google Play Books app has a carefully crafted interface from which you can browse both e-books and audiobooks, and you can get free classic copyrighted books like Treasure Island.Most other books offer access to their front pages as a free form.

When it comes to reading itself, you can choose between four types of fonts, and the app lets you adjust the text size and the space between words.

In addition, the application offers you the ability to display the original pages of the book on the screen as if they were in the form of the format of documents transferred.

This app is an interesting alternative if you want to enjoy classic original texts or books that contain special design elements that do not translate well in digital format.

Kubo
The author pointed out that the application "Kubo" empowers the reader to choose the font size and type, as well as the possibility to change the alignment of the text and add notes and even choose between two types of movement through which he moves between pages.

The app also provides an easy-to-access page that determines how quickly you read, how many pages you've played and how many hours you've spent reading a book.

Books apps help save and organize all books in one place (US Press)

Libby
The "Libby" application for reading books on the phone is somewhat different from the other mentioned applications due to the advantage of linking to local libraries in the United States, to provide users with free books and allows the loaning of audiobooks of novels, and just like with the actual library, the reader can borrow books for a specific period of time and provide Book requests for books that have already been loaned to other users.

In a related context, the Libyan application gives the reader the opportunity to bookmark, add notes, search for word definitions and switch between display color schemes, as well as choose within a range of fonts, so that the user to get digital pages such as desired.

The reader can easily adjust the font size and typing style.