The incorporation of mobile phones is persistent in the development of language learning, particularly in the EFL context. The present investigation aims to determine the impact of mobile-assisted language learning (MALL) applications on developing "learners" grammar proficiency. The current study employed a quantitative research method to explore MALL-assisted feedback in a WhatsApp group during the group chat. 60 Saudi male EFL learners, randomly assigned to the control and experimental group. Participants in the Experimental group practiced grammar in WhatsApp chat, whereas the same material was sent to the control group on Blackboard. The data was gathered by administering pre and post-test of grammar proficiency. Descriptive statistics and ANCOVA were used to analyze the data. The study's findings exhibited that WhatsApp group practice and feedback positively impacted learners' performance.