Following up on Montaner-Villalba et al. (2020), this research focuses on written competence in the English language. The huge advance in technology permits teachers to use mobile applications. This quantitative design research investigated WordPress, in its mobile version, on written competence in English as a Foreign Language (EFL). One treatment group (12 students) and one control group (12 students) of A2 (Common European Framework of Reference for Languages) EFL learners at a secondary school in Valencia (Spain, N=24) participated during the 2018-2019 academic year. While, on the one hand, learners from the treatment group utilized WordPress in its mobile version, on the other, learners from the control group used WordPress in its computer-based version. The outcomes proved that the learners from the treatment group significantly improved their level of written competence in comparison with the learners from the control group. Accordingly, this research recommends utilizing WordPress in its mobile version in secondary education. [For the complete volume, "Intelligent CALL, Granular Systems and Learner Data: Short Papers from EUROCALL 2022 (30th, Reykjavik, Iceland, August 17-19, 2022)," see ED624779.]