Uploading Images from your Mac to Instagram can easily be done without the use of any app or code writing. It takes only a few minutes and works like a charm.
Instagram is setup to work best with images that are uploaded from a phone. However I found a wonderful work around thanks to Macworld.co.uk that was easy to implement.
This works only if you use Safari, so open up the Safari browser and click on Preferences in the top bar. From there go to Preferences > Advanced
On the bottom of that window make sure that "Show Develop Menu in Menu Bar" has a checkmark next to it. If not click it on.
Still in Safari open up Instagram and log in.
Go back up to the Safari bar and click on Develop > User Agent > Safari- iOS 10 - iPhone
The Instagram page should automatically reload for you and look very much as if you had logged in with your phone and give you the same upload functions.
When you click on the camera icon you can choose any image on your Mac and upload it. When you hit Next in Instagram you can add your text, hashtags and even mentions.
Filters do not work and neither do video uploads, but having images upload is a hige plus regardless.