Yes they were very common on the Stug known as Ost-ketten? Lerenfort is a good site to browse and have a look at one of the links off the site theres footage of a T-34/75 being recovered from a swamp in Latvia....they reckon after swapping oil/plugs/fuel and a quick check over they had it running within 2days!
German tanks (I am thinking Mark 3 and Mark 4: they came as standard on Panthers and Tigers) etc bound for Russia got Ostketten - East Tracks.
Have an end-on look at a late-model Mark 3 or Mark 4 and you'll notice the side skirt extend well clear of the mudguards. You could fit either track behind these side skirts, but if they were flush like on modern tanks which come with wide tracks as standard, you couldn't fit the Ostketten.