If you by any chance are not using the Instagram app, but the mobile web, then you have just received some new improvements by the company. The Facebook-owned platform has now brought over the Stories feature to the mobile version of its website.
Now you don’t need to install the app to get the full experience and see your friends’ stories. If you don’t like this feature, then desktop is the only platform that is still missing the Stories, which is also missing various other features such as the ability to upload images.