Somehow, I never got around to posting my favorite apps of 2010, but if I had, Instagram would top the list. Nominally a photo filtering app, the true nature and strength of Instagram is its ability to instantly share photos of anything with anyone, and its committed community. In some ways it's like a simpler, much better designed version of flickr.

For a long time, I eschewed photo filtering apps and deleted this at first thinking it was the same. It wasn't until the second time I downloaded it that I saw the strength of its community of members and of the photos they were sharing. As I tapped around the "popular" page and sought people to follow, I glimpsed into lives around the world as they were lived.

Since then, I've been documenting New York through Instagram obsessively. At first, I was concerned it was keeping me from shooting otherwise, but I have since realized that if it weren't for Instagram I wouldn't be shooting at all. It's forced me to get out and shoot New York to present it to the people who follow me; I feel I have an obligation to them. And I've found that shooting with the iPhone gives a measure of invisibility that some of my other cameras don't quite afford.

Amazingly, the app has managed to garner quite a following even though it is available only as an app on the iPhone. A website version is, I believe, planned, but has yet to emerge. You can download the app here. And I can be found under user name "eugkuo".