Smart phones usually support a variety of e-book format. Some of the common format include: 1 MOBi:MOBi was an early e-book format commonly used in early smart phones and tablets. 2 EPUB:EPUB is one of the latest e-book format with higher legibility and searchability and support for more screen sizes and devices. 3. PDF-A powerful document format for creating high-quality, readable e-books. 4 TMT: TMT is a simple text format that is very suitable for creating simple e-books. 5. Blog: This is a format used to create web pages and e-books. There are many e-book format supported by the smartphone. The choice of format depends on your needs and preferences. Typically, users can use e-book reading applications to open and read e-books. These applications can support a variety of format.