2級ボイラー技士　過去問完全解説 is an educational and reference app developed by ayaka hirano. It is available for free on the iPhone platform. The app is designed to help users memorize past exam questions quickly and efficiently. It features a memorization function where important words are hidden, similar to a red check sheet, allowing for effective learning. The app provides clear explanations for all questions, making it easy to understand. It also offers features such as automatic collection of difficult questions and various study modes, making it ideal for last-minute exam preparation. The app's question and answer format allows for short study sessions during spare time. It is a valuable tool for those preparing for the 2nd grade boiler engineer exam.