細石 is an app that compiles a wide range of terminology used in haiku and waka. With this app, users can easily search for terms without the need to carry around a seasonal word dictionary, allowing for a more convenient way to enjoy haiku. The app contains approximately 50,000 terms, each with accompanying explanations, as well as around 7,700 example sentences related to haiku and waka.

細石 offers a free trial for one month, after which users can choose from four different packs to purchase depending on their needs. Whether you're someone just starting to study haiku and waka or an experienced poet looking to create more intricate works, this app is designed to cater to a wide range of users.