A heavy user of Instagram? If you're on your Mac, you might want to check out Photoflow. The app will cost you $5.79 but if you're a heavy user, that might be worth it. You get features like multiple account and stream support; wide search tools like being able to browse hashtags, locations, trends, etc.; desktop notifications for likes, comments, and new photos; mice and trackpad gesture support; and the ability to enlarge photos and videos by opening them or expanding the window. The app needs you to be running OS X Yosemite though. And no, it won't let you upload photos. No third-party Instagram client allows for that. 

Source: Lifehacker | Download: Mac App Store ($5.79)