Tykner.com is one of our favorite coding websites. With Tykner you can actually set up classes for your students. To me that is huge. Your students are no longer "playing" because you can assign lessons with a teacher guide and answer sheet then see students' progress. It will also tell you which standards the lesson covered. With this information you have data that will show student learning.
You can use the site on a computer as well as use an app on your iPad or Android device.
Tykner also has ready made lessons for Hour of Code that are fun! You can design a track for your Hot Wheels or complete a scavenger hunt or dance party with Monster High Girls https://www.tynker.com/hour-of-code