Well Google Chrome plugin almost supersedes the need for the Photo Gallery Maker app I made way back when: https://chrome.google.com/extensions/detail/nonjdcjchghhkdoolnlbekcfllmednbl. I installed this on my work computer to try it out, and slowly had to start installing it on my other computers when I found it missing.
It looks to me like it scans the page for any <img> tags and show them full size when you hover your mouse over them. It also turns out that it works with the galleries my app makes. Convenient!
