Picking a popular but inaccurate category, like Games for a non-game utility, to get more visibility rather than the category that actually describes the app's core function is a violation.
Usually caught when an app's actual functionality clearly doesn't match its declared primary category during the reviewer's hands-on testing.
"The category you have selected for your app does not accurately reflect its content and functionality, per guideline 2.3.5. Please select a more appropriate category."