Creating and handling an encrypted folder on sd-card for unrooted devices I'm looking for a way to create an encrypted folder on the sd-card and provide password protected access to its contents. Ideally, this would provide a UI to encrypt new files by moving files to it and retrieve them back. 

I know there is EncFS but it only works in rooted devices.
And also BoxCryptor which is only for Google Drive or DropBox.

I need a solution which would work with sd-card folders and on unrooted devices.
There are many available choices, depending on the features you need:


Cryptonite uses EncFS and requires root
LUKS also requires root and provides on-the-fly encryption (AES by default) to virtual folders
Eds provides encrypted containers and does not require root. It even is compatible to TrueCrypt.
DroidCrypt can encrypt single files or full directories. No root needed.
Encryption Manager is a file manager providing file encryption support, and so is AnDisk
FilesCrypter supports encrypted files and folders


And many more.¹ Just check the examples, and take a look at the "also recommended" stuff on their market pages to find more.



¹ disclosure: link goes to my Android site