Knowledge of multi-word units (MWUs) helps facilitate communicative fluency, and research on them has gained more and more attention in recent years concerning teaching methods and designing materials for second language (L2) acquisition. Incidental and intentional vocabulary learning are two dominant approaches to acquiring MWUs. In lexical studies, much research has examined the effects of these methods in various contexts. However, a gap in the research remains concerning materials development. This study aims to discuss various interventions that affect the teaching and learning of MWUs. This paper will highlight how more exposure and focusing learners' attention on particular MWUs is essential to the efficient acquisition of MWUs fluency. It can be achieved through intentional learning activities such as appropriately designed specialist digital flashcard-style computer applications and smartphone apps. Specifically, pedagogical implications are discussed when such applications employ either spaced repetition or a Leitner algorithm.