There is many way you can know who follows you and you can keep track of your followers easily on steemit.
I personally use 'esteem' app to do that. They have a 'notification bar' consists 'followers'. You can just tap on that and it will show 'by date' who follows you.
I also use 'Partiko' app. They also give a notification instantly if any one follows you. And you can easily see your numbers of followers and their profile on the top of your profile bar.
But I am not sure if there is any way we can get the list of people who unfollows us.
Information about who is currently following a user is readily available on front ends such as Steemit, Busy and Steempeak. It appears that all three list the followers in the order they followed.
If you want to be notified when someone follows you, using GINAbot on Discord is one way.
As far as who unfollows you, GINAbot will also notify you of that, as well.
Alternatively, you can go to https://steem.makerwannabe.com/, type in your username, and get a list of those who have followed and unfollowed you during certain intervals. The list provides these actions in date order for the time period you select.
The unfollow part isn't listed on the home page, but shows up in the results when typing the user name into the who follows text box.
The website, in spite of the domain name, is actually called Steem Followers and offers the ability to check on resteems.