A free program for Android, by Cloudfogger.

Encryption Manager is an application that lets you keep files on your SD card encrypted. You can use it without having to do anything else and it works for both Windows and MacOS.

What are the benefits of using Encryption Manager?

If you have some confidential data that you don’t want anyone to see, you can keep them encrypted and locked away from prying eyes. If you want to send a confidential message to someone, you can send it encrypted and they won’t be able to read it unless they have the corresponding key.

It is also possible to encrypt existing files in your SD card and keep them locked away from prying eyes. It is not only a great way to protect your data, but also a very convenient way to do it. The application can be used to encrypt files, images, videos, audio, and documents. The only thing that you need to do is to choose the file you want to encrypt and click "Encrypt".

Once the file is encrypted, you can open it and view it using the apps you have on your device or using the viewer that is included in the application.

If you want to send the encrypted file to someone, you can use the "send/share" option and send it to them directly or you can do it via email.

The app is available for both Windows and MacOS and can be used on any device that has an SD card.