This is a tool mainly for partition fixing, but the built-in file restoring function has come to handy a lot of times.

Particularly good for case: you know the position of the file and there is no same-named file under the same path (i.e. doesn't work for overwritten files). This tool recovers the file by looking at the file system journal.

The more powerful tool coming from the same developer team. This tool bypasses the file system, recovers files by looking at the content instead. This is the best shot for overwritten files.

NOTE: Many on web says that you can't recover overwritten files. The fact is if the blocks of the files are overwritten then you are out of luck, but usually overwriting leaves the old one intact by storing new content in new blocks.

grep, debugfs and blablabla…. They work by principle and look awesome, BUT it's hard to use them.