Tagsdock - Tag Instagram photos instantly from your iOS keyboard.
Instagress - Instagress is automation software for Instagram.
Buffer - Buffer makes it super easy to share any page you're reading. Keep your Buffer topped up and we automagically share them for you through the day.
Instagram Analytics by Socialinsider - Get better at Instagram marketing by studying competition
Tuigram - Share tweets on Instagram
Hootsuite for Instagram - Schedule posts and manage multiple Instagram accounts