Basically, the rundown of the app is this:
For children, the colors are nicely made, however some of the drawings aren’t mostly made for children(For example, there was a horror wolf drawing and two wolves fighting). These are suprisingly very well drawn, though! I don’t think you can use this app for coloring on a mobile device, because when you swipe each way the whole screen basically shakes.
As a result from this, my advice is to:
Download the app, screenshot the drawings you want to ref/color, then go to Krita, IbisPaint, or any other drawing app, and just import the photo. It’s your choice whether or not to keep the app, but I’d suggest to just delete it after.