iPhone: share with instagram

Instagram does provide an extension these days, but it doesn't seem to work for any content you try to share. It does work for the Photos app so it is possible that the extension only allows sharing images.

Reference:

http://www.techtimes.com/articles/163568/20160607/instagram-share-extensions-on-ios-perks-and-limitations.htm

https://9to5mac.com/2016/06/06/instagram-share-extension/

Update: I'm also an app developer and was wondering why the share button in my app(s) had Twitter, Facebook etc show up but not Instagram. Turned out if I disabled sharing text and urls and only provided an image to the share action, Instagram would show up as an option. So yes, the sharing extension by Instagram definitely only supports sharing images and will hide if it sees text, urls or other content coming in its way. BTW this is using iOS 11.

Since Instagram developers do not provide a share extension, this is not possible.

You can, however work around this using the Workflow application using a simple workflow that takes an image and passes it to Post to Instagram action.

Simply open your Instagram app, tap the center "camera" icon (the square with a circle in the middle) your photo library from your iPhone will appear at the bottom of your screen and you can "select" a photo from there. Then tap the "next" word at the upper right of your picture until you are satisfied with any filters or alterations you want to make, then continue to hit "next" again and your photo will post to Instagram.

Re upload the app you missed a step that it asks to access your pictures I did the same thing I have a iOS 6

Access the photo from Instagram, and if you're like me, you won't see the "channel" in this case, Instagram to share the photo to, BUT it doesn't matter as you are accessing the photo FROM Instagram, so add text if you want and select post (while ignoring the fact that you haven't selected one of the default channels), and it WILL post to Instagram. I just verified this.

Submit a support ticket or e-mail to the developers asking for this feature

There is no way to share it straight from the photo gallery as of iOS 7. It is much easier to share it straight from the instagram app. You can simply do so by pressing the bright blue camera photo on the bottom of the screen in instagram. You will then be directed to some filters you can choose.
If it still does not work, try quit the instagram app through multitasking and re enter the app.
It might be possible to share straight form the photos app in iOS 8 or you could (not recommended) jail break to get it.

The app may have been rerouted to another directory not visible to the parameters of your iPhone's camera roll. Try reinstalling instagram and check its properties. It should work fine the next time around.

It might be easier to try opening Instagram first and then picking out the picture from your photo gallery. If the picture you're trying to share isn't in your gallery, you can take a screenshot of it in order for it to appear in your gallery. From there you will be able to upload the picture to Instagram. Hope this helps :)

Sorry but you don't really have any control over this. Some sharing panels offer a "Open In..." option in the bottom-right corner. If you check an application that does offer this option (for example Dropbox) you'll likely find Instagram in that list.

For some reason Apple doesn't provide that "Open In..." option in the Camera or Photos apps.

The Facebook and Flickr options are hard-coded by Apple. They always appear in the sharing list even if you don't have the applications installed.