Once it is released, you can use aurora store to install the app. Boost will never be released on fdroid, since it is not open source and I doubt it will ever be.
Thanks I've been using that it's pretty cool. Jerboa is what I'm using right now. I read through the privacy policy of Boost and I'm glad I decided not to use it. Loved it for reddit but since there are foss alternatives I'd much rather use them