I developed a tool called Multisearch that allows you to input a list of titles (50 max) with a wiki project and get back a link to the page (if it exists) and the QID of the Wikidata item:
This tool is useful when you're matching datasets and you want to quickly get pages and QID's for a list of titles (think street names, personal names, cities, etc.)
Unfortunately for Wikidata it doesn't quite work. The API call i use doesn't work for Wikidata because entities are not pages. I think there are probably two API methods, but both are not sufficient. wbsearchentities can only query one thing at a time. wbgetentities has an option to query multiple labels, but you need to specify sites, which makes it effectively the same as querying a Wikipedia instance (and hence, not useful).
So basically what i need is an API method to query multiple labels and get back if the label exists (and what its QID is).