Created by friends Pek Pongpaet and Brandon Leonardo, Pinstagram presents a user's Instagram images in a Pinterest-style waterfall view.
Users can pin Instagram photos on their Pinterest-style board, as well as 'like' and comment on photos, search keywords and share images on Facebook, Pinterest and Twitter.
Pinstagram launched last month on the web, but yesterday (June 12) expanded onto the iPad.
The new app allows users to browse their Instragram photos on the iPad screen.
All swipe and gesture navigation on the iPad is supported, and the app has been optimised for the Retina display in the new iPad.
Pongpaet and Leonardo developed Pinstagram as a "weekend project" after thinking that combining the two fast-growing web properties would be a "funny concept".
Speaking to Mashable, Pongpaet said that the startup opted to launch on the web and iPad as this is where Instagram - the photo sharing app now owned by Facebook - is currently not available.
"If people are already using Instagram on their iPhones, it would be duplicating Instagram's effort," Pongpaet said. "We'll never be a better Instagram than Instagram."