iBooks the default e-book reader app for the iPad/iPhone/iPod touch. The ebook can be downloaded from the online stores, but you can also convert your PDF documents to a format compatible with iBook (ePub format) and transfer them to your iDevice.
- Download and install Calbre (available for MacOS, Windows and Linux).:
- Launch Calibre and click on the "Add Books"
- In the window that opens browse for the PDF document and click "Open".
- Next click on the "Convert books" button
- In the window that opens, set the output format (EPUB). Via the same window you can select a photo or any image as a book cover.
- Click "OK" and wait for the conversion to be completed.
- Transfer the ebook to your iDevice, via iTunes.