From: http://www.squidoo.com/top-5-ebook-reading-apps-ipad-iphone

Apple iPads and iPhones are great devices for reading ebooks. There are many ebook reading apps available for you to choose from, and they’re free! This lens will introduce you to some of the most popular, show you where to download the app, and where you can find some ebooks for it.

1. Apple iBooks App for iPad and iPhone

The iBooks app is the most native Apple ebook reading application that you’ll be able to find for the iPad and iPhone. It currently has a 3.5/4 rating from reviewers in iTunes. If you are new to ebooks and you have an iPad, this app will be a good place for you to start. Since it is so integrated into the device, you won’t have to worry about using any external software. You can also use it to read your own PDF files.

Where to get the app: Download iBooks from Apple via iTunes. This app will work on both iPad and iPhone.

Where to find ebooks: iBooks includes Apple’s iBookStore, where you can purchase ebooks and then download them directly to your iPad or iPhone. It’s very similar to downloading music from iTunes, so if you’re familiar with that, you’ll be downloading ebooks in no time.

2. Amazon Kindle App for iPad and iPhone

The Kindle App was created by Amazon to allow you to read your Kindle ebooks on devices other than a Kindle. If you can’t find an ebook in iBooks, you might be able to find it on Amazon for the Kindle. This way, you can make use of Amazon’s large ebook selection on your iPad without having to buy a separate Kindle ebook reader.

The Kindle App will let you start reading on one device, and pick up where you left off on another device. Amazon has many classic books available for free that you can access through the app.

Where to get the app: Get the Kindle App for iPad, or get the Kindle App for iPhone

Where to find ebooks: The Kindle App is made to be used with Kindle ebooks that you purchase from Amazon. Find those in Amazon’s Kindle Store.

3. Kobo App for iPad and iPhone

Kobo has free e-reading apps for both iPad and iPhone. You can use these apps to read ebooks that you’ve purchased from Kobo, even if you don’t have a Kobo eReader. You can search for ebooks, buy them, and download directly to your device with the Kobo app.

Where to get the app: Download the Kobo App for iPhone, or the Kobo App for iPad

Where to find ebooks: If you’re planning on using the Kobo app, then you should buy ebooks from Kobo. You can download the ebooks directly with the Kobo app, or you can find them online.

4. Stanza App for iPad and iPhone

Stanza is a free ebook reading app made by the company Lexcycle. Stanza is a useful app because it will allow you to read ebooks that you downloaded from sources other than Apple. It can currently read these file formats: ePub, eReader (.prc), PDF, CBR, and DjVu. They even provide you with multiple methods of transferring your ebooks between your computer and iPad or iPhone.

This is for slightly more advanced users. If you’re new to ebooks, you’ll have an easier time if you stick with one of the apps mentioned above. Stanza is great for ebook users who like to find ebooks from independent ebook retailers, whether they’re shopping around for better prices, or have found an ebook that’s not available from other sources.

Where to get the app: Download Stanza for iPad and iPhone

Where to find ebooks: I recommend eBookMall’s Palm eReader ebooks for the most current/popular titles. Stanza will also read many other ebooks in ePub or PDF format, providing that they are not protected by DRM.

5. Barnes & Noble Nook App for iPad and iPhone

The Nook App from Barnes & Noble lets you read all of the Nook ebooks on your iPad or iPhone, without having to own a Nook eBook Reader. Barnes & Noble’s Nook system is unique in that it will let you lend ebooks with their “LendMe” software. You can also sample any of the Nook ebooks for free before you buy.

Where to get the app: Download the Nook App for iPad or download the Nook app for iPhone

Where to find ebooks: If you want to read ebooks using the Nook App, then you should get ebooks from Barnes & Noble’s Nook store.

BONUS: Bluefire Reader App for iPad and iPhone

The Bluefire Reader App is an up-and-coming ebook reading solution for the iPad and iPhone. The special thing about this app is that it works with Adobe’s “Content Server” which means you can use it to read DRM-protected PDF and EPUB ebooks on your iPad and iPhone. This was not possible (as far as I know) before this ebook app was released. This requires “authorizing” the reader with an Adobe ID just like on any other device. They also claim that you can open library books with it, but my guess is that will depend on the library.

Where to get the app: Download Bluefire Reader for iPad or iPhone

Where to find ebooks: You can use Adobe PDF and EPUB ebooks from just about any ebook retailer. This is great because it means that you’re not tied to iBooks or Amazon, or any other specific ebook seller. Try eBookMall’s Adobe PDF and EPUB ebooks.

Related links:
1. 7 Featured EPUB eBook Readers
2. How to convert PDF to Epub to read on iPad, iPhone and iPod Touch?
3. How to transfer PDF to iPad?
4. 8 Common eBook Formats