sorry i didn't find this post, when checking the forum.
having a dropdown "+ tags" and an extra dropdown "- tags" would be perfect to select tasks by "client"-tag but not "exported"/"invoiced"-tag.
to keep the ios-interface slicker, you could also have one "tag-filter" with each tag as:
[-] TAG_NAME_1 [+]
so one status: no / neutral / yes could be selected in just one section (e.g. background color: red / neutral / green) instead of two.
this function would be very much appreciated
thanks