I'm giving this two stars instead of one, because it probably does work as a standard image gallery, and because I understand that Instagram recently changed their requirements, so now a more complicated setup is required in order to display an Instagram feed. However, I think the description should be updated to reflect this (it currently says it's easy, and no API key is required, which is false) and the documentation should be more detailed. For someone who's not a developer, the instruction "Create an Instagram client ID" does not tell me how to go about doing that, and the process is not intuitive. I have tried asking for support, but have not received any clarifications, and as a result, I am unable to use this add-on to display an Instagram feed, which is the reason I purchased it. After a lack of response to my questions, I have requested a refund, which I think is valid because it does not do what it says at a beginner level, as advertised. However, I have received no response to the refund request either. I honestly can't relate to the other reviews that reference great support. :-(

Finally i found a gallery for Concrete5 that really can handle a large amount of large image files!

Since Gallery Box does not create thumbnails in the files cache, there will never be a problem with recreation of thumbnails, when a gallery page is called after the cache has been cleared. Many Concrete5 galleries create thumbnail files in the files cache. When the cache is cleared for some reason (updates or other changes), all these files are lost and depending on how many thumbnails have to be recreated when a gallery page is loaded for the first time after clearing the cache, it can take ages for the page to be displayed, especially with larger galleries.

Gallery Box instead pulls all images (including previews) from their original paths, which amazingly is still totally acceptable regarding the perseption of loading time, because of the use of an efficient lazy loading function, in clever combination of a progress bar and spinners as temporary placeholders for the thumbnails.

Since there are no thumbnail image files created, also retina resolution is not an issue. Lightbox images, as well as previews are all perfectly displayed at best resolution. I'm using sets of image files at a width of 1800px for nice display quality also on retina screens.

Lastly, because i personally didn't like the transition "elastic" for the lightbox (lightcase), i changed the settings of js/lightcase.min.js (which thankfully is not minimized) a bit to my personal taste:

NIce instagram gallery ;) Also great assitence (if you need it)