With Marvel App, you can easily make wireframes for apps. It's good for testing new versions of the app.
Founder - Favoroute
We just started using an InVision competitor called Marvel, for mobile and web prototyping. So far, it’s really nice. It’s a great way to collaborate on work coming from design.
Founder & CEO - Knowtify
Marvel is a super simple design, prototyping and collaboration platform that allows anyone to bring their ideas to life.
Visit the website: https://marvelapp.com/