Move, Copy and Remove your WhatsApp files To Your Removable SD Card with the help of this app.
With a really easy to use interface you will be able to choose between copying, moving and removing your files.
There is also an added option to select keeping and not moving the files in the period of time of your choice.
Warning: once you move your WhatsApp files to your SD Card you won't be able to access them directly in the message they were sent, but you will be able to send them like a normal image, document or video.
Disclaimer: Files To SD for WhatsApp is a third party app and is in no way affiliated with WhatsApp Inc.