I used HP Quick Test Pro (now HP Unified Functional Testing) from PB 10.5 and PB 11.5.
It was ok in terms of UI testing tool for PB.
The tool was also certified for Appeon Web, and in fact Appeon's help up to version 2016 contains a dedicated section "Testing Appeon Web Application" too. I tested that too and was indeed working as expected.
In HP UFT there's been added support for PowerBuilder 12.x.