What are some alternatives?
When comparing DownloadIG.com and 4K Stogram, you can also consider the following products
GramPhotos.com - View Instagram Full Size Profile Pictures
GramPhotoz.com - View & Download Full Size Instagram User Pictures
GramDL.com - Instagram Photo & Video Downloader
Downloadagram - Official Instagram photo and video downloader.
GramDownloadz.com - Instagram Post Downloader
Insta Dp - With InstaDp you can view instagram profile picture for free in full(original) size and download it right away.