In a nutshell: For me, it's nothing, so such photo-share apps. But since many Droid users have been waiting for it because the egg-phone users have had this for so long, I just say that it is here (Instagram for Android).
For those who don't know what Instagram is, I like to explain it in short words. It is an app that allows you to take photos and then edit/retouch them with X filters(etc.). After that, you can post it on the Instagram network or on Twitter or Facebook.
It is intended for users who see interesting motifs on the go and then like to take a snapshot. Alone happy is doof, therefore you can publish it via "Instagram" and let others participate in the "fun at the Freud".
I don't know if Instagram is chargeable on iOS, but for Android you can use everything completely free of charge and pay nothing. So if you've been waiting a long time for it to finally come out for Android, you should go to Google Play and download Instagram right away.