Cryptomator

Site: cryptomator.org/
Purpose. File/folder/drive/encrypter with virtual drive support.
Country: Germany (Skymatic UG (haftungsbeschränkt))
Price: Freeware
Opensource: Yes

Imagine you are working on a top secret project, and you don't want anyone to know. Or you live in a bad neighborhood and you are afraid that someone comes and steals your stuff.

Or, imagine you buy, or use, free of charge (?), cloud space on any provider, be it Google,Microsoft,Dropbox,Amazon, or any of the other "minor" space providers. But there's a catch. In the hidden/small lines, the companies you give your files to, are entitled give access to 3rd parties (or do it themselves) to search through your data, hunting for whatever they wish, for marketing purposes, to know how you live, what you listen to, where you go, what do you like most...and imagine, just imagine, you don't want that.

Or, imagine you're a bastard that downloads copyrighted data likes movies or music and want to avoid being caught by the authorities.

You're stuck, unless you encrypt your data. That's what Cryptomator is for. You create a vault on disk, and Cryptomator gives you a virtual local drive. When you copy stuff into that drive, it is encrypted, content, file name, folder name, and in the end you lock your vault. After it is locked, if you go to the original location of the data, you won't see anything but garbled stuff.

To unlock the vault, of course you need a password, it better be a good one, and that's it.

Never ever save your password online, store it in your head, or encrypt it somewhere in your home.

What's the best about cryptomator ? It's "client-side", so you never need to give your password to anyone, any site. As long as your computer is secure (no keylogging trojans), you're safe.

Being clientside is specially important when you create the vault on a "sync'ed" folder, meaning, a spot that will be sent to the cloud by your local cloud replication service.

And that's about it. Until today, it was not broken. 

Each vault has its own 256 bit encryption as well as MAC masterkey used for encryption of file specific keys and file authentication, respectively. So they say.

And the best best best of all ? It's open source (well, so they say, I must check, tbh), so you know there's no backdoor implemented.

Transparent, fast (well, slower than a normal access but still good enough), encryption. What else do you need?