Get paid apps for free on Android legally!

Although, this method solely relies on chance, I happened to get Five Nights At Freddy's, Wolfram Alpha and Terraria for free on my Android device. Download Amazon Appstore from
http://www.amazon.com/getappstore and sideload the APK into your phone. The instructions are in the link. It won't break your phone. Now check every day for free app deals in the app store.  Good subreddits to follow for updates are /r/freebies, /r/efreebies and /r/gamedeals. Sometimes it takes Amazon Appstore a while to get the updates for apps unlike Google Play.