With some keyboard layouts such as the standard Canadian French layout, or the Canadian French Dvorak layout, "dead keys" are used. That is, to type "â" you type ^ and then the letter a, but the ^ doesn't appear until you type the letter a. 

However, in gnome shell this doesn't work, because it types the ^ directly. Accents such as àèòìöäïëüâêîôûç won't work. Thus, you won't be able to search for application names that contain them.