This study investigated English-as-a-Foreign-Language (EFL) learners' preferences, activities, rationales, and barriers in utilising mobile technologies within pre-class sessions in a flipped learning context. A total of 279 university EFL learners participated in a closed and open-ended survey study. The findings revealed that learners preferred to utilise four types of mobile technologies (i.e., ChatGPT, TikTok, YouTube, and English Club) in flipped English learning, and they also engaged with many online learning activities (e.g., generating automatic content, improving oral skills, sharing English skills, revising written texts, translating sentences, or organising texts). Furthermore, learners' mobile technology utilisation was due to several rationales, including flexibility, self-paced learning, interactive content, multifaceted materials, and collaboration. Lastly, technical, pedagogical, financial, and psychological issues remained the most influential barriers encountered by learners, while other issues, such as, social and cultural, infrastructure, and privacy or security concerns, were found to be less impactful impediments. For university stakeholders and teachers, the findings help to identify strategies for flipped learning design, leading to syllabus writing, material development, and assessment method. The findings are also useful for learners to improve the flipped learning process and manage barriers properly.