Update README.md to add SimpleLister

Author: mmccaff

README.md

@@ -95,6 +95,7 @@ Click a link to jump to the appropriate section. Both sections are organized alp
 * Saijo's Tools List - https://saijogeorge.com/best-marketing-tools/
 * Show HN - https://news.ycombinator.com/showhn.html
 * Side Projectors - https://www.sideprojectors.com
+* Simple Lister - https://simplelister.com/
 * SimilarSiteSearch - http://www.similarsitesearch.com/tips.html
 * Slant - https://www.slant.co/
 * SnapMunk - https://www.snapmunk.com/submit-your-startup/