Icons

1, emojipedia

This site contains a huge number of emoji expressions, kind of like emoji dictionary.

And, one emoji has many kinds of styles:

2. iconfinder

If we want to make a set of 2.5D style PPT, it's hard to find a unified style of icon on the Internet, but in this website, all the 2.5D materials, are categorized according to the style:

And the quality is also very high:

Download, there are a variety of formats to choose from:

3, basicons

Website provides a large number of linear icons,

And, the right side of the page can also set the size of the icon and line thickness:

The most important thing is that these are free and commercially available, direct download can be used.

Photos

1, foodiesfeed

This site, all of which is a number of pictures of food, is very rich.

Inside the picture material, can be downloaded for free:

2, NASA picture and video library

This is a website specializing in providing the planet universe gallery, the material is first-class, and also provides video material.

When searching for a keyword, but also in chronological order to filter:

And, this site also provides different sizes, very thoughtful:

3, imgbin

The world's largest Png material site, basically included a common free key picture. Material classification is very rich:

If you click on one of the tabs, you can also see a more specific classification:

And the quality is very high:

If you are usually not good at keying, you must collect this site.

Demo category:

1, dimmy

This is a lesser but better site.

Why? Because the number of prototypes of this site is small, but each exquisite:

Each prototype can be adjusted border style, color, if you need a transparent background, check the box.

2, mockuphone

This prototype site is characterized by each prototype are classified in detail:

Operation is also very convenient, just select the model, the corresponding size of the interface can be uploaded:

3, mockup

This site has a variety of prototype.

There are billboard prototypes:

There are cell phone prototypes:

Computer prototypes:

There are many more, so I won't give you an example.

However, the samples on this site are all in PSD format and need to be opened in PS.