When adding a new app at https://dev.twitch.tv/console/apps/create, the first field in Russian reads "Владелец", which translates to "Owner". In reality, this field is intended for the application name, and it reads just "Name" in English.

The correct translation would be "Название" ("Name"), or "Название приложения" ("Application name").

P.S. It's also impossible to change your language while on the dev.twitch.tv subdomain, and you have to navigate to the main site in order to change language.