Give https://ui-cloud.com a try!
According to the site:
"UI-Cloud collects the best UI element designs from the internet all over the world and provides a search engine for you to find the best UI element that you need.
We are aiming to create the biggest platform for designers to showcase their top user interface designs and for developer to get the best UI elements for their project easily and quickly."
I’ve started playing around with it, and it looks good so far.
Nice share, there are a lot of these websites around.
Here are some others I use:
I also use: https://dribbble.com
Dribbble has some of the best designers in the world and a bunch of them share freebies all the time. If I need a button I always check here with a simple search like (button psd): https://dribbble.com/search?q=button+psd
You will find cool shit like this:
Update, Instead of searching dribble for freebies you can now also use: https://freebbble.com
All the free files in one place.