Both Pano2VR 5 and krpano 1.19 have “VR” modes that display flat panos and stereo pairs on VR devices. You can make tours with either one.
With krpano, you must use the “webVR” plugin, which provides all the VR device support, then coding the rest of the tour is almost as in previous versions. You need a lot of experience for that.
If you don’t want to code krpano, Pano2VR does everything by a UI (which can be confusing, but is very productive once mastered; and there are very good tutorial videos). However its player is not so fully developed as krpano’s.
Kolor Panotour Pro is a good but expensive GUI front-end for krpano, that many people like. I suppose it now supports VR mode.