The present study investigated the effect of using an English vocabulary learning application called “Drops” as a tool in helping English as foreign language (EFL) young learners in pre-intermediate level learn English vocabulary. This app was designed to be installed into smartphones with Android and IOS system. To examine the program’s effectiveness, two groups of students (40 learners in each group) in two kinds of genders were set up as an experimental group (those with “Drops”) and a control group (those without “Drops”). Knowledge of the vocabulary after homogenizing learners tested before and after using this app by pre-test and post-test PET multiple-choice test, to assess the impact of the using this app on vocabulary learning on young EFL learners in Iran. The results of the study showed that the learners who use the application significantly outperformed those in the control group that learn vocabularies by traditional methods. At the conclusion of the study, the researcher realizes that 1) using technology such as digital games should be highly emphasized where learning vocabulary is the focus of the study, 2) teaching vocabulary traditionally in the control group, though was less significant than the experimental group in this study, should be also utilized as the second priority in teaching vocabulary in class, 3) the findings revealed no difference in learning English vocabulary based on gender.