GEL is simply the new launcher (with various fun things that I will not cover here) released with 4.4, but it’s just standard on Nexus 5. If you have Nexus 7 (both variants) and Nexus 10 and so, you need to download and install it. It’s just a must on any nexus device as it simply makes it look like I think 4.4 SHOULD look.
So, how do you add a Widget to GEL?
it’s actually pretty simply and if you have had an htc phone in the past, this will look familiar. Simply longpress an empty part of the screen and you get a page where you can look at settings and add widgets and such. Pretty simple.