Webstagram: You need to connect your Instagram account in order to get started. You can then look at your feed, your own photos, photos you've liked, what's "hot", which are the most popular hashtags and accounts, and a photo of the day. You can submit your photo to be picked by posting a photo with the hashtag #photoftheday.
One of our favorite features of Webstagram is seeing which filter people used to take their photo.
Webbygram: Webbygram's layout is a bit more like Tumblr. The photos are shown in a stream, and you can rollover the photo to like it, but to comment you must click on it first. After clicking on it you can share the photo through social media, too (Facebook, Twitter, Pinterest).
You have three viewing options on Webbygram: your feed, the most popular photos, or your own photos. Webbygram is great if you like scrolling through photos
(Images: 1. Etsy, 2 & 3. As linked above)