I studied Russian for 2.5 years in high school, and another two at university. I took it pretty seriously and am in general interested in languages/inclined to learn them. But I still estimate that it wasn’t much more than 350 hours of classroom time, probably not quite doubled by homework/out of class practice, plus a month-long home stay/exchange experience (which wasn’t as useful as it could have been, as I was early in my Russian studies and still struggled to make conversations—I should have done it a year later).
>tl;dr — probably got less than Google’s suggested 1100 hrs
I wound up at a moderately high intermediate level, and because my study was formal I have good grammar, which makes me sound more impressive than I am. And I have used Russian instead of English all over the place, including in some surprising places like former USSR friends Laos and Vietnam.
What I lack are slang and a large vocabulary. I can put any word into any case, usually correctly, but may not have the right word to do it to. I can talk about snowplows but not cooking, and I can give or get detailed directions better than I can trash-talk a football team.
I recommend getting at least some formal instruction instead of just using an app, ideally in-country, so you can get basic structure stuff drilled into you and questions answered by someone who is correctly informed. Then immerse for actual real-life use and use apps for vocabulary and expressions.