Mac: If you're still on the hunt for the perfect to-do list on OS X, the awesome but expensive Things is just $25.99 this week.
Things is probably one of those apps you've wanted to try, but not for $50. If you're a fan of the GTD productivity system — or a variant of it — a lot of people swear by Things. It's very polished, and it might be worth it to you at $26. You can try out a free trial on their site before purchasing too, so give it a shot — just make sure you make up your mind before the deal ends on January 31.