Elucidate allows you to drag and drop a scanned PDF onto the it and then a fully-searchable one is created in its place through the power of optical character recognition (OCR). Using your PDF editor of choice, you can highlight text, define words, use built-in text-to-speech functionality, and make comments.

Over 90 different languages are now supported, and the app is faster than ever. Elucidate will even separate pages from face-down book scans and output raw text files (enable in Preferences).