Lost Photos, the Mac app that combs your email accounts for image files, is available for free all day Friday, and for $0.99 for the rest of the weekend. Ordinarily $2.99, the app automates downloading all the image attachments you’ve sent or received from your Gmail, Yahoo, AOL, or iCloud / MobileMe / .Mac accounts over the years, then gives you the option to post them to Facebook or Twitter. We tried it ourselves, and think Lost Photos offers a good value at $2.99; at $0, getting a better deal is actually impossible.