It's just the convention for placing adverbs- still generally goes between the auxiliary and the present participle in progressive forms (I am still going) and before the auxiliary in perfect forms (I still haven't done it) or main verbs (I still think).
It can come at the end, which can be used for emphasis- I believe it still, I am Duchess of Malfi still. It sounds strange to me in your example because there's no clear reason for it to be there without more context. I believe that it may come in end-position in Irish English but am not certain.
It can come in other places- in conversation, it can be used at the beginning to shift focus or return to a point like 'anyway'.