Default Free open source image galleries

I have tried a varied mix of image galleries and even though they are generally otherwise very good they are always lacking someplace or another. (Particularly missing my preferred sorting and problems with exif, for some reason they don't read date and time correctly for some images)
So I would like to try an open source one to be able to modify it's behavior and see what's going on.

Has anyone got a list of free/open source image galleries for android?

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