Simple! Instagram already provides the functionality to upload photos through a web browser (You can read about it here), but sadly this feature is locked to mobile web browsers only. Windowed overcomes this issue by pretending to be a mobile browser, allowing you to visit the Instgram mobile website directly from your Mac or Windows PC.
*All of your interactions including login are done directy with Instagram, Windowed is simply a tool that lets you access the Instagram mobile website. We don't have access to your account so you don't have to worry about giving a 3rd party your account information.
I'm a photographer and computer engineering student who was frustrated that there was no easy way to upload photos to instagram directly from my computer. I created this initially to improve my workflow but I realized that many others had the same problem as me. I'm releasing Windowed as a free application to help other photographers like myself, Happy Shooting folks!