Yup! I reckon followers by date would be a very welcome one to see who your most recent followers are for multiple reasons. And posts reposted by others too. I hope you really have the chance to pulish and finish soon the work on your own API to get embedded all those valuable tidy bits already available in your app too. :)

I didn't have time yet to start working on it. I'll let you know when ready!

On other hand, through the odd side of things. ¿Would you think you could develop some way to know who has seen your posts? I mean, ¿Extract and get from the steem blockchain the steemian's usernames of those behind and under the Views Counter in your posts?

That's not possible. For what I know, that is an API of steemit, not the blockchain. And there is no way that I know on how to extract who saw the post. If someone know somethings more, please let me know ;)