You can use [this jsfiddle][1] to use the StackExchange API to find questions that only have one tag. Specify the tag at the top of the script in `var tag = 'taghere'`.

Alternatively, use the [Data Explorer][2].


  [1]: http://jsfiddle.net/FY8hQ/
  [2]: http://data.stackexchange.com/gaming/query/163894/questions-with-a-single-tag?TagName=version-differences