Ять is an Android app developed by Dmitry Kanunnikoff, which falls under the category of Utilities & Tools. The app is free to download and use. Its main function is to translate modern Russian language to pre-revolutionary Russian language, which was used in 1918.

The app provides a significant level of accuracy in translating modern Russian language to its pre-revolutionary variant. However, it is not yet fully developed and may contain some errors. The app has a feature for reporting any translation errors, which can be accessed through the app's menu or by sending an email to the developer's email address.

Overall, Ять is a useful app for those interested in learning pre-revolutionary Russian language. It should be considered as an initial step towards familiarizing oneself with pre-reform spelling.