Android operating system and the applications that run on is boiling in the world for these days and it will continue to be hot topic for many years coming, thus Android mobile applications increasing everyday steadily and rapidly. Android mobile applications with low usability can lead to reduce the productivity of users and incur cost for business. Android mobile applications usability is critical for their adoption especially because of the mobile device have small screen, and awkward keyboard, thus there are about 100 different devices have been used Android as operation system with different screen size, with or without hard keyboard, some mobile devices contain two screen, and so on from the differences.
