Postedo - Simple Instagram scheduler that publishes for you
HopperHQ.com - Fully automated Instagram scheduler. Create and schedule your posts online.
Uplet - Uplet is an easy-to-use bulk Instagram uploader for Mac.
InstaGhost - Upload photos directly from your PC to your Instagram account without needing your phone, schedule...
Grum - Post on Instagram from your computer!
Later - Schedule and manage your Instagram posts