Obesity is a major health problem around the world. Saudi Arabia is a nation where obesity is
increasing at an alarming rate. Mobile apps could help obese individuals but they need to be
usable and personalized to be adopted by those users. This paper aims at testing the usability of
a fitness mobile app” Twazon”, an app in Arabic language. This paper presents an extensive
literature review on the attributes that improve the usability of fitness apps. Then, it explains
our methodology and our set up of a trial to test the usability of Twazon app that is popular in
Saudi Arabia. The usability attributes tested are effectiveness, efficiency, satisfaction,
memorability, errors, learnability and cognitive load. The trial is done in collaboration with
participants from the Armed Forces Hospitals - Taif Region in Saudi Arabia. The results
highlight that the app failed to meet with the usability attributes.