Windows/Mac: You've probably received a heap of photos via email in the past few years, but you might not have ever added them to your photo library. Lost Photos is an app that scrubs your email for all those missing pictures, and it's free this weekend only.
We've talked about Lost Photos before, and it's a rather handy little app. Lost Photos is always free on Windows, but Mac users usually have to pay $2.99. This weekend, it's on sale thanks to AppyFridays, so head over to the Mac App Store and check it out.
Lost Photos (free)