We have been working in this video technology for quite a long time. "Content is the king", by saying this content will help correct accent, colloquial word meaning, right use. The scenes will help to relate with real situations. In your monetization idea you could also add connecting your app/application with institution, training centres, online influencers/teachers to use the snippet of your software. Also expose the API, so that it could be white label-ed (for local distributor), or could be integrated with any LMS. For more advice, please connect with me sandeep.bera@tranzsilica.com or call me
https://clarity.fm/sandeep-bera