Dragonframe can visually de-squeeze an image shot with an anamorphic lens.
In Dragonframe 5.2 and newer, the setting is part of the Camera setup in Scene|Cameras.
In Dragonframe 5.1, the setting is called 'Anamorphic', and is available with most cameras in the 'Camera Settings' area of the Cinematography workspace. There are various de-squeeze ratios you can choose from: 2.0, 1.6, 1.33.
In older versions, the setting is called 'Stretch', and only offers 'Anamorphic', which is 2.0.