Wiser 2 will not download on to ipad

[Mal]

I purchased a home with an ipad A1395 installed in the wall that was running Wiser 2. It worked fine until one of my kids messed with the ipad and logged us out of it. He didn't know the password (it was set by previous owners) and he tried a number of different passwords until he got permanently locked out of the ipad. Only way to get the ipad to work was to reinstall the operating system so it is running iOS 9.3.5 now. The ipad works fine. However when I try to download Wiser 2 from the app store it says "Wiser 2 is not compatible with this iPad". I checked the app store  and it says I need iOS 9.0 or later to run Wiser 2 so should work. And the iPad used to run Wiser 2. I would also note I have downloaded Wiser 2 on to other newer ipads in the house and they work fine. Can anyone help me with this problem?