Excuse the pun in the title, but the extension doesn't work. Install it on a wiki, and you will never get a single row in any of the tables, and the footer will stay blank. It will never show any view count.
This is because the database transaction system was extracted without keeping the working assumptions it had built in.
ViewCountUpdate::doUpdate used to increment a page_counter field in the page table. As being the page table, it has a row for each page, and the column exists (default to ).
In the extension, it is migrated to a separate table. A table that is empty by default. In order to work, it must insert a row for each page before it can update rows.
As it is, doUpdate() does a conditional search for page_id, finds nothing, and increments nothing.