Same here though I use Busuu. Used Duolingo in the past, to be fair there’s not that much difference between the two.
Been dreaming of a FOSS alternative, where people work together to make the best possible ever-improving courses, and all is free and customizable to your every need. That would be so awesome ! Surely some day some one will make this happen, right?
That’s a lot of words for saying: focus on buying houses, and keep them so no one else can buy these houses.
Also it’s not at all obvious that you’ll accomplish it before others get houses/hotels.