This app needs some tool to switch COMPLETED ads, back to ACTIVE. Some users click "SET AS COMPLETED' button because they think, they need it to finaly publish the ad. Some of them, if they dont sell the item want simply publish ad back.
Maybe if you change word COMPLETED to CLOSE AD helps a little.
When ad is set to completed is not visible on main page, but we still have some links on sidebars and on "last post" section to this ad.
Also mobile version of application looks a little unattractive when you are in category... besides application is great!