Web:
In order to save videos or photos that you receive from your families all you need to do is:
Open the image you wish to save.
Right click on the image with your mouse.
Select 'Save Image As' from the list of options.
Rename the image and manually type a .jpg extension at the end of your file name.
Choose where you want to save it.
Click 'Save.'
For further reference, please see screenshots of Step 3 and Step 4 below.
*Please note: This works for both pictures and videos.
Mobile:
1. Open the conversation that has the image you want to save.
2. Tap on the "Image."
3. Tap on "save" to download the image.