How I Use It
Tynker is used at my school as part of our Coding unit in our 1st-4th grade weekly 1-hour Technology Class.
Students actively use it the bulk of class during this unit (which is near the start of the year), and then end Tech Class with 10 minutes of Tynker at the end to help them calm down and be ready for their next class.
What works is the more explicit re-directions the program offers compared to Code.org or Scratch. The only tricky component is trying to make sure students aren't jumping ahead around units, since the units must be turned on by class and not by individual student.
As a technology teacher, I've used Tynker, Code.org and Scratch to teach the concept of computer programming to my 1st-4th grade students.
After having them use all three, I took a vote. I gave all three as options for my kiddos. Consistently, nearly every student chose Tynker. A few students chose other programs, but these were generally students who were already high readers so I don't believe it was because the program had too much of a textual burden.
Overall, my students told me they like Tynker more because it gives more clear re-directions when a student is having trouble passing a course. Code.org tends to give "hints", but sometimes these hints are actually wrong. It may say "try adding a *left* block" but the actual block that needs to be added next isn't that block.
Tynker, while more heavily relying on text, provides more clear guidance for stuck students.
My kiddos with lower literacy tend to need help on trickier Code.org puzzles anyway, so the textual instructional weren't really frustrating to them. They needed help on Code, they still need help on Tynker. However, kiddos who have more developed reading skills are able to use the Tynker directions with little to no help from me. This frees up about 20% of my class that previously was getting stuck with some frequency.
It may be that I only teach each class for 60 minutes a week and I don't have as much time to address misconceptions full-group, but Tynker is an excellent fit for my school!