I think everyone will agree with me here, but no one saw this coming. Flickr has just released an official Android app which lets you add filters to your pictures within seconds, just like Instagram. With Instagram taking their time releasing an Android version of their highly popular picture sharing app, Flickr must have seen the opportunity and have taken advantage of it.
The app lets you of course sign in with your Flickr account, takes photos, add filters and share them on Flickr, Twitter and Facebook literally within in seconds. With Flickr having a much larger user base and an actual website where you can view all your pictures they are way ahead of Instagram already.
This is no doubt a stab in the heart for Instagram with Flickr being their number 1 competitor.