Making the gap to conversational is probably always going to require more than just an app. You've got to hear real people speak the language and interact with them, maybe it could be done with a lot of very expensive work with LLMs and advanced text to speech generation but there's a big gap between the basic grammar and vocab that language apps teach to really understanding a native speaker. French in particular is rough for this though because of the... loose... association between the spelled word and the ways it's spoken.