It is a great resource for free icons and png image archive. I found everything I was looking for my projects. Really very useful.
Pixabay - Over 270,000 free photos, vectors and art illustrations
Freepik - More than a million free vectors, PSD, photos and free icons. Exclusive freebies and all graphic resources that you need for your projects
Flaticon - A database of free vector icons.
PNGEgg - PNGEgg is a library of transparent sticker png images for designers.
Pexels - Find the best free stock images about Browser Home Page. Download all photos and use them even for commercial projects.
Pixelfy - Retarget the people who clicked on your Amazon link. Rotate links. Create superURLs, 2-step Brand URLs, Storefront URLs and Rotate them, add a Facebook pixel or Google Analytics. Get your Amazon listing ranked fast and track all the data!