Ocellus allows searching for and viewing more than 200K images that we have extracted from scientific articles as part of my TDM project. The images (and a whole lot of other data) are stored on Zenodo that is hosted at CERN in Geneva.
I wrote Ocellus to primarily view the images. It might turn into something more, but I am also determined to keep it very simple and fast. Ocellus is also very mobile friendly. I continue to work on it to make it even faster.
Ocellus itself is a 100% client-based app in that, there is absolutely no magic happening on the server. However, Ocellus leverages another tool I wrote called Zenodeo that does all the heavy lifting of querying data from various locations including Zenodo/CERN.
You too can write your own application using the Zenodeo API. Check out the Zenodeo documentation