旧版書籍用ターゲットの友1200　英単語アプリ is a free educational mobile application developed by Obunsha Co.Ltd. This app is compatible with Android 9.0 and is aimed at helping users complete the "英単語ターゲット1200" published by Obunsha. The app offers a variety of features such as online competitions with users from all over the country, a self-practice mode that allows users to choose the specific area they want to focus on, and an audio function that allows users to listen to the pronunciation of words and phrases. The app also includes a ranking system for users to compete with each other and measure their progress. Additionally, users can customize their avatars using items earned through completing tests and winning competitions. The app is free to use and does not require users to own the book to use it.