This is awesome! I've been using Photoshop for these types of projects and it takes so long...

Pros:

• Animating with this tool looks so easy!
• Easily create responsive designs and can quickly test without having to deploy every little change.

Cons:

• $199 per year is steep, but it's not as expensive as Photoshop and so much quicker to design an app.
• It's not obvious if these designs can be exported to HTML or whether you'd have to rebuild the actual website.