Is there a way to track gross number of twitter followers gained?

Yes, you must use FollowerAudit Twitter follower tracker tool - https://www.followeraudit.com/tw... This tool will let you track your follower's growth rate and unfollowers stats based on a daily, weekly, and monthly basis. It calculates the gross number of Twitter followers gained including unfollowed followers. You can also track followers growth of other public Twitter accounts and compare your performance with them.