App Inventor for Android
This MIT-created platform uses visual blocks to allow students to create apps that can be exported to Android devices. Large library of tutorials that get as advanced as SMS texting and GPS. Requires a Google Account to use.
This free iPad app uses a visual programming language similar to Scratch to help kids learn the basics of programming logic, such as sequencing, loops, variables, functions and conditionals.
Detailed video tutorials for Scratch and App Inventor for Android. Advanced students can check out tutorials on C#.
Created at MIT, Scratch popularized visual blocks as a way of learning programming. But don't let the easy interface and cute graphics fool you--users can make and share anything from simple animations to fully-fledged games.
SNAP!'s visual blocks support higher level computer science concepts like recursion, procedures, and continuations, making it appropriate for even college level intro classes. While it doesn't have the same social functions of Scratch, SNAP! can work with the Nintendo Wiimote and LEGO Mindstorms NXT. Comes with a manual and sample projects and can use much of Scratch's documentation as well.
Game creation software that allows users to make playable apps for iOS, Android, HTML5, Window, and Mac. The game logic is programmed with visual blocks. The official site has forums and a crash course to get you started.
Inspired by Scratch, Tynker has a dashboard to allow teachers to create a more structured way of teaching code with visual blocks. Includes assessment, classroom management, lesson plans, and a built in tutor.