Abstract: In the era of rapid application development which emphasizes heavily the rapid prototyping and iterative delivery, it is imperative that software developers take the time to properly plan the software development phases. With the emergence of cloud computing and mobile cloud computing software developers are tempted to jump in and write code without planning. This practice can lead to resource waste, thus making the use of software development methodologies an imperative. This paper proposes five UML diagram models for a cloud accounting app.