Character incomplete achievements tracker.

[natassja72]

Currently there is a drop down list on default achievements pane that allows filtering achievements by All/Earned/Incomplete status. Would it be hard to create an addon that would add 4th option to track current character incomplete achievements?
I'm in the process of slowly completing some easy achievements on my main toon that I have completed randomly years ago on different toons and I need to manually hover over each achievement in each of the sections and subsections to see what toon completed it.
I've tested several achievement addons and couldn't see any of them provide such functionality.
There is RaidAchieveFilter addon that partially does the job, but it only works on raids and dungeons.