Despite the popularity of mobile apps for second language (L2) vocabulary learning, the specific app features that influence various aspects of vocabulary knowledge remain uncertain. This study compares the effects of two newly developed apps, Sayra and Zabanyad, on L2 receptive and productive vocabulary acquisition. Additionally, the perceived advantages and disadvantages associated with each app were probed. Forty-two Iranian English as a Foreign Language (EFL) learners were divided into two experimental groups (using Sayra or Zabanyad) and a control group. Participants completed the New Vocabulary Levels Test (NVLT), a pretest encompassing the vocabulary from both apps, followed by an immediate receptive vocabulary posttest and a delayed productive vocabulary posttest. Semi-structured interviews were also conducted with learners in the experimental groups to gather qualitative insights. The results indicated that users of Sayra significantly outperformed both Zabanyad users and the control group in the receptive vocabulary posttest. However, no significant differences were observed among the groups in the productive vocabulary posttest. Qualitative findings revealed a generally favorable perception of Sayra, for integrating game-based elements, such as leaderboards, rewards, and challenges. The findings have implications for L2 teachers and developers of mobile-assisted language learning (MALL) materials, highlighting the potential of gamification to enhance vocabulary learning.
