Teaching grammar to EFL students has always been a challenge for EFL teachers. Many studies have acknowledged the role of using mobile apps to remove this problem. Therefore, the present study was conducted to see if the use of English Grammar Ultimate Software app can enhance the use of verb tenses by Iranian intermediate students. To this end, thirty-two students participated in this study based on their performance in a Quick Oxford Placement Test. They were randomly assigned to experimental and control groups. Each group consisted of 16 learners. Then a test of grammar was administered to two groups as the pre-test to assess their knowledge of simple present, simple past, present continuous, past continuous, and simple future tenses and ensure their homogeneity. Learners in the control group were taught these tenses through traditional language classrooms and received no extra treatment at all. However, learners in the experimental group were taught those tenses through English Grammar Ultimate Software app. Finally, in order to measure the effect of the treatment, a posttest was given to both groups. The results of the comparison between and within groups showed that the participants who had benefited from mobile-assisted learning had a significantly better performance on the post-test than the participants in the control group. The findings of the present study can have implications for material developers and EFL language teachers teaching grammar.