Do you find yourself having difficulty downloading the MaxSold Ninja app on your iPad or the newer iPad Pro?
The trick is to search MaxSold Ninja using the iPhone filter in the App Store: https://appsto.re/us/WP2B9.i
It's an iPhone app that works on iPads (although we have not tested it on the Pro). Since it is an iPhone app, you need to use the drop down to search iPhone apps as opposed to iPad apps.
If you still have issues with the app, feel free to contact MaxSold (firstname.lastname@example.org). Good luck with your cataloging!