I think everybody on here is constantly keeping an eye out for what to host next. Sometimes you spinup something which chugs along nicely but sometimes you find out you’ve been missing out.
For me it’s not very refreshing or new: Paperless-ngx. Never thought I would add all my administration to it. But it’s great. I probably can’t find the thing I need, but I should have a record of every mail or letter I’ve gotten. Close second is Wanderer. But I would like to have a little bit more features like adding recorded routes to view speed and compare with previous walks. But that’s not what it is intended for.
What is that service for you?
The easiest thing: We use a motion sensor to automatically turn on the light for the stairs. You wouldn’t need Home Assistant for that, but with a little more configuration you can adjust the light levels and colour temperature based on the time of day (not as disturbing at night). We have two rooms which have problems with humidity in one a fan is automatically turned on (basic) in the other a dehumidifier is triggered based on the outside and inside temperature because there are large windows which are producing a lot of condensation otherwise. Now the really specific stuff: My daughter has Diabetes and we need to manage her blood glucose levels. There are alarms but ideally you would act before they are triggered. So we hooked her blood glucose levels to a light in our bedroom which turns on at night if her levels are getting out of bounds at night. That way she isn’t woken by the alarm, but by one of us and can go back to sleep mich quicker.