In a widget-based app, hovering with the pen over the screen created a lot of stack overflows. The reason was that in src/android/jar/src/org/qtproject/qt5/android/QtSurface.java, dispatchHoverEvent() is called when hovering, and in this method the first method invocation on the m_accessibilityDelegate returned false. The second method invocation there then happened on dispatchHoverEvent() of the same object, leading to endless recursion. I don't know what this is supposed to do, but as a temporary fix, the three lines doing the endless recursion can be commented out:

//                SurfaceView view = (SurfaceView) this;
//                Method dispHoverView = view.getClass().getMethod("dispatchHoverEvent", MotionEvent.class);
//                return (Boolean) dispHoverView.invoke(view, event);

The pen seems to work fine in the "Qt5 Everywhere" app I downloaded from the Google Play, so it seems to be widget-related.

(Second issue from original report moved to QTBUG-38379.)