I use Cryptomator. https://cryptomator.org https://cryptomator.org I'm not sure of the program's technical specs, but it is multi-platform, available on mobile

I use Cryptomator. https://cryptomator.org https://cryptomator.org I'm not sure of the program's technical specs, but it is multi-platform, available on mobile, and is easy to use. I am able to have a shared set of secured documents with various non-technical family members. I'm not overly worried about the Goverment having my files and I feel it is good enough to keep Dropbox and other hypothetical 3rd parties from my most sensitive documents.