Many makers have their own free recovery programs, usually rebranded versions of some regular tool. These may be more successful than the generic versions as they can fall back on a database of memory layouts and mapping algorithms for the vendors cards (something that is usually rather deficient in freeware tools). But they won't work on third party cards and might be worse than useless on counterfeit cards.
Another approach, by sellers of heavy duty data recovery software, uses pattern recognition heuristics to recombine lost sectors into meaningful files - but software like that tends to be far from free, and works best with compressed files (as a pattern that creates a meaningful compression can be accurately computer validated, other than a picture, or worse, a series of pictures only fractions of a second apart).
