The service is available on iPhone 3GS/4, iPod touch after the third generation, iPad, and Android OS2.1 update1 and later. It is basically web application but the user interface is designed well and looks like a native application. Android version is released as a native application.
There are two ways to read EPUB contents, adding them yourself and reading other users' contents. Contents holders or self publishers can publish their own contents and promote them using a social graph of Twitter.
- jig.jp provides applications for feature phones including very popular full browser, jig browser. Along with dramatic penetration of smartphone, the service is its first major service targeting only for smartphone.