Which free app has the most Negative comments?
paid app refers to Type = 'Paid'; negative comment refers to Sentiment = 'Negative'; paid app with most negative comments refers to MAX(COUNT(Sentiment = 'Negative')) where Type = 'Paid';
SELECT T1.App FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE T1.Type = 'Free' AND T2.Sentiment = 'Negative' GROUP BY T1.App ORDER BY COUNT(T2.Sentiment) DESC LIMIT 1