Again, you have two issues - you are violating the copyright of the original song writer and you are violating the copyrights of genius.com.
Since you agree you are using the website of genius.com you may have agreed to their terms of service which are:
Commercial Use: Unless otherwise expressly authorized herein or by Genius' express written consent, you agree not to display, distribute, license, perform, publish, reproduce, duplicate, copy, create derivative works from, modify, sell, resell, exploit, transfer or transmit for any commercial purposes, any portion of the Service, use of the Service, or access to the Service. The Service is for your personal use and may not be used for direct commercial endeavors without the express written consent of Genius.
Those terms of service may create a contract between you and genius.com. So you not only have the copyright issue you also may have a contract law issue.
Further, you are welcome to question whether others are violating the copyrights of authors - but that won't get your app approved, will it? And if you look into Genius.com you may discover that they are respecting the copyrights of others through their copyright policy here:
h ttps://genius.com/static/copyright
Finally, while 'free stuff' allows you to do certain things with the stuff, it does not allow you to do other things - and 'displaying to others' is one of those things that you don't get to do. And even if your app is 'free' it doesn't mean you can ignore your obligations under copyright and trademark law. You may have a path through fair use but it is a narrow path - and Apple seems to think you have strayed from that path.