The iBooks app is better. But Amazon Kindle Store is cheaper and has a superior selection.
The books
Publishers are responsible for creating and making available the books in each store. Sometimes a book is exclusive to one store. In that case, you have no option of where you purchase it.
When a book is available in both stores, you must compare the price and quality on a book-by-book basis. This is easy to do because both stores offer free sample chapters. Books tend to be better formatted in the iBooks Store than in Kindle's Store. This can be critical for some genres, such as technical/programming books with graphics, code samples, and tables.
The ecosystem
iBookstore purchases can only be read on iPhone/iPod touch/iPad/Mac. Kindle purchases can also be read on Amazon's dedicated Kindle devices, Microsoft Windows, iOS, BlackBerry, Mac OS X, Android, webOS, Windows Phone, as well as in a web browser.
The apps
iBooks app:
- better interface (you even can turn off the skeuomorphic design features, if you prefer)
- it has less features, but the features it does have are better: dictionary, highlighting, type/fonts, footnotes, navigation, look and feel
- better PDF support
- iBookstore built-into-the-app for convenient browsing and purchasing
Kindle app:
- Sharing feature where you can publicly publish snippets from your book to kindle.amazon.com for linking-to in Twitter/Facebook. Example.
- Amazon creates an email address for you to send documents to your Kindle via email. E.g. yourname@kindle.com
- Con: You have to jump out to the web browser to browse and purchase content.
On an iPad, I prefer reading in iBooks because Apple executes the fundamentals better. Amazon's Kindle app has some nice differentiating features, though. All that said, at the end of the day, nothing's better than reading a basic novel on a standalone e-ink Kindle device.
No.
As of version 4.5 of the kindle app for IOS in pdf searching is not available.
As of version 1.10.7 of the kindle app for OS X in pdf searching is available.
Best Answer
Yes, in both the iBooks and Kindle apps, you can search the full text (excluding text in images) of the book you are currently reading. Here's how to do that in each app:
iBooks app
While reading a book, tap the screen. A magnifying glass icon becomes visible in the top right, along with other controls. Clicking the magnifying glass icon brings up a search box. After entering your search term in the box, iBooks presents a list of results from the current book, underneath the search box.
Kindle app
Similarly, while reading a book, tap the screen. At the bottom a magnifying glass icon will become visible. It works much like the iBooks search feature.
What about searching across all books?
If you wanted to know whether you can enter a search term at the top-level of these apps and have them search across all books stored in the app: No, currently neither iBooks nor the Kindle app have such a feature.
However, I have seen this capability on the Kindle device itself – I own a Kindle keyboard model and there is a "search my items" option available that will search all books on the device for a given term.