remove closing ?> line to match other plugins
tweak metabox name on job creation sheet
display Ninja Form submissions along with each submission

relies on the Ninja Form submission post always being one post ID previous to the WPJB submission post; in a high-use scenario, this may break down. A better option would be to collect match IP address and server request time in each form, save as custom post metadata, and match using those values. See stash a547064 for first steps towards that