Right now, for some languages and writing systems, there's not many subtitle font options; for example, in Persian (and I'm assuming Arabic as well) there's only one font option which is Arial. It'd be great if the app at least recognized all of Google Fonts catalog and/or even better, allowed us to upload from our own custom fonts from our devices. One resource that might be useful for this is: https://developers.google.com/fonts/docs/developer_api