What are some alternatives?
When comparing GramPhotos.com and GramDownloadz.com, you can also consider the following products
PostDownloader.com - Instagram Photo & Video Downloader
GramDL.com - Instagram Photo & Video Downloader
Insta Dp - With InstaDp you can view instagram profile picture for free in full(original) size and download it right away.
DownloadIG.com - Instagram Photo & Video Downloader
JustForLink - Simple way to download photos from Instagram to your Mac, PC, tablet or phone from any browsers.
4K Stogram - Free Instagram Downloader for macOS, PC and Linux. Search, download or backup Instagram photos shared by any user. Follow your favorite photographers and stay tuned!