This is (I think) the most complete user interface elements pack to date on Graphicriver 
It includes so much stuff it’s hard to make a list but I will try:
- input field and text area
- check-box
- radio buttons
- drop-down list
- list box
- calendar
- simple button
- CTA buttons
- social login button
- interface buttons
- pixel icons with 36 pixel icons / glyph
- breadcrumb
- step progress
- progress bar
- tooltip
- rating stars
- pagination
- switch
- slider
- video player
- audio player
- 55 infinitely scalable vector icons for web apps
- tabs
- notification messages
- special offer badges
- …more to come
Comments, questions and ideas are welcome as usual 