If you want know how to see Instagram full size profile photo on your iOS or android then have download the "Qeeky app" from the Google play and iOS app store. After downloading the app, follow the steps given below to view full size instagram photo.
1. Open the "Qeeky" app on your device.
2. Enter the "username" of the profile in the search bar, whose pic you want to view.
3. Click on the "circular photo" to view the full-size profile image.
For more read - https://allinsider.net/how-to-view-instagram-full-size-photo/