FlairBuilder

FlairBuilder is an amazing tool for wireframing your next website or mobile app. You can design responsive websites and apps.
It has an online viewer through which you can see and share your work with others.

Salient Features

• CSS grid
• Customizable Typography
• Built-in Animations
• Comes with multiple behaviors

Head over to the below link to get a 15-days free trial. It is available for both macOS and Windows.
Download Here