Barron's Algebra App

I had a shock yesterday when I had my Algebra I class do the first quiz in Barron's Algebra App.  In order to unlock the game, the individual student had to score an 80 or better answer 20 problems that only used signed numbers and the four basic operations.  An example of a problem was -2 + 5 -(-3) =
The highest score was 65%.  These are 9th graders who took pre-algebra last year and took a basic college math class last year.  This app gave me a way of obtaining student data in a quick and easy manner so that I know what I need to scaffold.  I think the next time I have them do a quiz such as this on an app, I will record student scores.
I tried using nearpod in my last class yesterday and we had issues with it.  I found out later that there are at least two other classes using the internet at the same time because only 5 students were able to log on out of a class of 20.  Now I have to figure out a way of being able to use it or give it up.
As far as virtual manipulative websites, I am looking at the individual websites to see if they work on the iPad.  It appears that due to several using Java applets, there may not be any apps out there that would allow me to access any of the sites.