Photo app Picplz expands its social reach

The past few months have seen the launch of two hot San Francisco startups with mobile photo-sharing apps — Instagram and Picplz. Today, Picplz announced that it’s catching up with the competition on the social networking front, by adding support for photo-sharing site Flickr as well as blogging services Tumblr and Posterous.

I’m not sure if it’s fair to paint the two startups as being in a head-to-head rivalry, but both apps seem to be built around the same basic idea: Users take a photo, add a filter, add location information, then share the photo within the app and other social sites. The startups even share an investor in Andreessen Horowitz, though partner Marc Andreessen has said that he will take a more passive role in Instagram.

Picplz has the advantage of working on both Android and iPhone, while Instagram seemed to be ahead in support for social networks. Now the tables have turned, with both apps allowing you to post to Twitter, Flickr, Facebook, Tumblr, and Foursquare, and only Picplz supporting Posterous.

At this point, the exact laundry list of services probably isn’t that significant, but I think it’s important for these apps to have a wide social reach — the selling point of an app like Picplz is the ability to share your photos anywhere, not just within the Picplz community.

Picplz was co-founded by Dalton Caldwell, who also founded music-sharing service Imeem. The company recently raised a $5 million first round.