The line down the back makes me think Oak Toad (Bufo quercicus), which are much smaller than an American Toad. They reach adult size at about 1-2 inches. Here's a photo.

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And this link has some info on it: http://www.uga.edu/srelherp/anurans/bufque.htm

If your friend found it in NJ, it might be something else, since that's just north of its range.