I have been working as a ClassFlow Ambassador this year which means I have been getting a lot of practice using the site to make lessons!
I have been working with some of the teachers in my district helping with test prep. I just finished putting together a series of five "lessons" that are designed to be test prep practice for our third graders. Each "lesson" has 12 test like questions which gives students practice in subtraction with regrouping, rounding, multiplication, measurement, and fractions. All together there are 60 practice questions.
The reason for this push is that our state will be going to mandatory computerized state testing next year with the option to begin this year. We took that option (as we are a 1:1 district). These "lessons" (I am putting quotes around them because they are more practice then lesson...but the system calls them lessons) are designed to expose students to computerized test questions in math.
ClassFlow is free to use (you have to make an account) and allows you to deliver interactive lessons to students on their devices (so they can respond on their tablets and iPads). If you are a 1:1 district I would definitely check it out.
Here is a link to all 5 math practice sets for anyone wanting to check them out and use them.