I've used my N800 as a flashlight on many occasions, so I'm not sure why Maemo Mapper would need a night mode beyond that.

Maemo Mapper does remember addresses to a certain extent in some buffer, but I have never been able to use the buffer in Maemo Mapper -- I would expect to be able to tap on an address and have it pop into a form, but it doesn't work for me.

But in general, I think Maemo Mapper is great.