Principle

Lottie is a mobile library for Android and iOS that parses Adobe After Effects animations exported as json with Bodymovin and renders them natively on mobile!

Framer is a JavaScript framework that makes creating realistic prototypes a breeze – complete with filters, spring physics and full 3D effects. Framer Generator is a desktop app that imports the resources and folder hierarchy from Photoshop files (Sketch coming soon). Import your design and immediately start to add interaction and animation.

It is the easiest tool used to turn your UI/UX design ideas into highly interactive prototypes for mobile, desktop, web, all the way to IoT. ProtoPie runs on macOS & Windows and the player app is on iOS and Android.

Express your creativity with Material, an animation and graphics framework for Google's Material Design and Apple's Flat UI in Swift.

It is a set of user experience development tools that unify design, prototyping and implementation of high quality, native apps for iOS and Android.

Origami is a free toolkit for Quartz Composer—created by the Facebook Design team—that makes interactive design prototyping easy and doesn’t require programming.

It is a Mac app used by designers around the world to create interactive and animated prototypes of their app designs. It lets designers quickly make interactive prototypes of their mobile, desktop, or web apps.

Fiber UI Kit is the perfect starting place for your next project. Each element has been designed to work independently or as one seamless flow. It’s a full-fledged prototype with customizable components.

Pop is an extensible animation engine for iOS and OS X. In addition to basic static animations, it supports spring and decay dynamic animations, making it useful for building realistic, physics-based interactions. The API allows quick integration with existing Objective-C codebases and enables the animation of any property on any object. It's a mature and well-tested framework that drives all the animations and transitions in Paper.

Avocado is an open source interaction design toolbox built by​ IDEO.​ It ​enables designers to make quick interactive prototypes without writing a line of code.​ ​Built on top of Facebook's Origami framework, Avocado provides ready-to-use patches that can be easily combined to create fully-customized prototypes.​ Official announcement: http://labs.ideo.com/2014/05/27/avocado/

Supernova converts any mobile design to full-fledged native applications, giving the developers extra time to do actual coding. No need to export resources, write navigation, connect it to components created by hand, read styles, apply styles, copy-paste information..

It is an open-source design and prototyping platform meant for cross-domain teams. Non-dependent on operating systems, it is web-based and works with open web standards (SVG). For all and empowered by the community.

Create animations that flow naturally from the user's movements. Rather than animating properties for a set amount of time, impulse takes a start position, end position, and velocity.

Mockplus is a web-based collaborative design platform which connects designers, product managers and developers, built for making design faster and easier.

Equipping you with hundreds of symbols and dozens or styles configurations, it makes sure the design stays consistent across all of your applications and platforms.

Prott is a new and powerful prototyping tool for designing and developing mobile apps. Through rapid prototyping you can shape your ideas instantly. No matter where you are, you can test your prototypes and share your ideas and comments. Continually improve your design without writing a line of code.

It is a prototyping tool that lets you design, test and get feedback on your app ideas quickly and without needing to know how to code.

Simple and fully customizable Sketch UI kit to helps you design and showcase your Facebook Bots. All elements are turned into new branded Sketch symbols, so prototyping has never been easier.

Uizard is an AI-powered design tool released in 2018. Uizard's easy-to-use drag-and-drop editor and its AI features help users design and prototype user interfaces for web and mobile applications.

Creo is designed to help people build native mobile apps in minutes. Design and Code merged in a new powerful tool.