On the web at Behance.net:

To view Work in Progress navigate to the For You page.

The Work in Progress strip will appear above new projects published by your creative network and project recommendations, on the For You page. You can also view a Behance member's Work in Progress directly from their profile. 

To view a creative’s Work in Progress, tap on their profile picture located in the strip. Any user with a blue circle around it indicates that they have new Work in Progress content. When viewing Work in Progress segments, the viewer will automatically move from one person’s to the next.

To skip to the next segment in a creative’s Work in Progress, click on the segment you wish to see. You can also use the left and right arrow keys on your keyboard.

To pause a segment in someone’s Work in Progress, click on the segment you wish to pause and hold down your cursor.

Using the Behance iOS app:

The Work in Progress strip will appear above new projects published by your creative network and project recommendations, on the app homepage.

To view a creative’s Work in Progress, tap on their profile picture located in the strip. When viewing Work in Progress segments, the viewer will automatically move from one person’s to the next. To skip to the next segment in a creative’s Work in Progress, tap on the right side of your screen.

To skip between people’s Work in Progress, swipe right or left on the screen.

To pause a segment in someone’s Work in Progress, tap and hold the screen.