Based on the context, "BLU" likely refers to the (jouet éducatif/cartes flash parlantes) described in the HOMESTEC product search results .
Paper Title: The Role of Interactive Phonetic Flashcards in Early Language Acquisition: A Case Study of "BLU" (French/Bilingual Edition) I. Introduction
Sets include 224 to 510+ words (Montessori-style).
Unlike tablets, this educational toy engages auditory and tactile senses without the negative effects of screen time.
Analysis of "BLU" Interactive Educational Flashcards (French/English).
The impact of technology-assisted learning in early childhood education (ages 2-6).