In order to have a very simple tool to share the pictures with my family, I finally decided to set up a simple gallery site myself.
Since 'godaddy' hosting only supports php, so only those php galleries are googled. Without much surprise, there are actually a lot of open source tools for that. However, none, seems really fit my requirements, though I consider my requirements are really simple and common.
But that did match with my observation of recent years of project management, it's probably true that every single customer has his own bizzare requirement, even if he believes these are most normal and valid ones.
Among around the 10 tools I have checked, I have finally tried out 'TheThig' and 'folio-gallery'. Both are easy to set up, but the second one is 'really' easy to set up. Folio gallery has only one single PHP page, and need no DB, so it's definitely lighter than others. Though the coding style is not really great, but it's module design is at least reasonable.
I would probably change a few lines of source code of the tool in order to use it.