If you are an avid reader and don't mind reading digital books, then you should be using Apple's Books app on your iPhone and iPad. This app has flown under the radar for a long time, as it rarely gets much fanfare and its updates are relatively quiet. iOS 13 adds a nice feature - it lets you set reading goals that help you keep track of how many minutes a day you are reading and how many books you've read so far in the year.
The iPhone can read almost anything on the screen aloud. With Speak Screen, iOS will read a web page or book in the background, even while another app is being used. Reading controls are conveniently located in a pop-up Accessibility menu, which minimizes automatically.
Getting content offline can vary widely between different sources and apps. When you're depending on an iPhone, iPad or iPod touch to get through a long flight or commute, it means downloading music, books and video directly to your iOS device. Finding books to read without a data connection requires browsing the books that are stored locally in the Books app.
Apple has consistently added features and content to its stock reader app. Originally known as iBooks, on iOS 12 and later the app has been renamed Books. iPhone, iPad and iPod touch users may notice that when reading, Books automatically enters a night theme when the room is dark. This Dark Mode can be manually controlled and customized directly in the Books app.