This sounds like something I think a lot of people would want. I know I do. It’d be particularly great if one could also simultaneously update/edit micro.blog posts as well, particularly when one is syndicating them to micro.blog via a feed. (Or does micro.blog accept fat pings to update the content? and maybe add some UI to indicate it was edited at a later date to prevent people from doing a bait and switch post?)
The closest thing I can think of currently for this is Aaron Parecki’s open sourced Quill app which works via micropub (to both WordPress and/or micro.blog hosted, or to WordPress and then syndicated via feed to micro.blog). I suspect that, depending on how one authenticates, Quill could (?) be aware of syndicated copies to micro.blog and be able to edit the posts on both platforms after-the-fact. Since Quill is a (progressive?) web app, it could be used as a mobile app on both iOS and Android.
As an aside, I notice your WordPress blog shows a generic: “This Article was mentioned on micro.blog.” line in many of your comments. Are you doing this by design, or are you unaware of the Symantic Linkbacks plugin which will help to take webmentions to your site and help turn them into more friendly looking replies within your comments section?