Just a little UX note: I'm trying to register and I get a "Username is invalid" error. I have a special character in it ("-") so I guess that's why, but it would be a good idea to state your validity rules in the error message.
I live in a place where winters are long, days are short and skies are either gray or dark.
Having the opportunity to see the sun even for a couple of minutes when coming out from work is a great feeling that has a big impact on people's mood and mental health especially at the tail end of winter. Electric lights don't have that effect.
I also spend more of my non-working time outside and I'd love to be able to go out for a run without a headlamp earlier in the year.
I am a twitchy/boderline-ADHD type of guy. When I don't get (a lot) of exercice because of lack of time or whatever other reason I simply cannot concentrate and spend my day changing position in my chair and losing focus.
My sit/stand desk solved that issue and when I'm standing I feel a lot more focused. Even if in the end I'm not moving that much more than while seated, it feels like a world of difference to just be able to step around and move my legs a bit.