From Daniel Gary:
Instance is not an official Instagram client and is not created, maintained, or approved by Instagram.
Instance has all of the features of the paid version, only free!(With Ads)
The only fully featured Instagram client on the market. Register, upload, comment, like, follow, find your facebook friends; All from Instance!
What's new in this version:
Version 1.3 changes:
Rebranded as Instance
Pull to Refresh
Find Friends will work with Facebook
Registration bug fixes