If someone on your Christmas list owns an iPhone or iPad, then the gift of apps can definitely be worth giving. Giving an app is a built-in function for iOS; here are some useful options to consider.
Let's face it, no matter how good looking it is, nobody really wants to pay $5.49 for a RSS reader. So, for those news junkies on your list, there's no better gift than Reeder, which is easily the best looking, most useable, and most feature-rich RSS reader for iOS.
Editorial is an incredibly powerful text editor for the iPad and it's the perfect gift for everyone on your list from programmers to writers. With Editorial, they'll be able to write their own automation scripts to power up their workflow, browse through various versions of their work with Dropbox version support, or write anything they want in Markdown. Basically, they can make Editorial whatever kind of text editor they want, which makes it the perfect gift.
Spotify (from $11.99)
There are lots of streaming music services to choose from, but Spotify is the biggest and best-known. While anyone can now use Spotify on their mobile for nothing, a Premium account allows ad-free access and lets you choose individual tracks. You can buy a one-month gift subscription for $11.99, 3 months for $35.97, 6 months for $71.94 or a year for $143.88.
Photoshop Touch ($10.49)
f you have someone on your list who loves to edit photos no matter where they are, there isn't a more powerful option than Photoshop Touch. Of course, it's not nearly as feature-packed as its desktop counterpart, but the iPad version holds its own. With it, they'll be able to modify their photos in a variety of way, work with layers, and much more. The iPhone version ($5.49) isn't nearly as good as the iPad one, but it's still passable considering that it's essentially a simplified version of Photoshop on a phone
VNC clients aren't an exciting gift, but considering Screens is over $20, it's not something that most people are going to buy for themselves. With Screens, they'll be able to dial into their PC, Mac or Linux desktop from anywhere with Wi-Fi, so they'll never have to be away from their computer for long. Screens has a stack of features too, including keyboard support, iCloud syncing and fullscreen mode. With the right setup, they'll basically be able to turn their iPhone or iPad into a desktop PC.