Vidmate is one of the best known applications currently available for downloading videos and songs from online services like vimeo, dailymotion, youtube and tons of other multimedia portals. With this highly recommended app, you’ll get to download fro practically any video site.
Malware and viruses are harmful for devices.
Any software that modify system without your permission is a malware.
But vidmate is not doing any modification in your devices software. There are too many other apps there which are doing same but these are not harmful for your devices.
So use Vidmate there is nothing like a virus or malware in this app.