Proto.io

Proto.io is a web-based prototyping platform for UX designers, entrepreneurs, product managers, and marketers. It offers an intuitive drag-and-drop interface and over 250 UI components. The platform allows users to create prototypes that mimic the behavior of their native counterparts. It also offers a large selection of digital assets, including static and animated icons, stock images, and sound effects. Proto.io offers a 15-day free trial. The pricing after the trial period is not immediately apparent on the website.