Two items I can think of: a bluetooth/wifi controlled multicolored lightbulb and reusable K-cups

Rather than setting up strips of lighting along my ceiling in my apartment, just changing out the bulb in my lamp is a really simple way to have full customization of a room's lighting. Nowadays, I find myself just lying in bed, changing the color and brightness of the bulb on my phone as I listen to music, changing it to whatever feels the best. Even for regular use, changing how bright or soft the white light is can be useful.

As for the K-cups, it makes for a really easy method of making coffee at the office. Due to a long commute, I have to wake up earlier than I would like to arrive at the office on time, and it generally leaves me little time to prepare coffee at home. During the summer I usually prepare cold brew the night before, though in fall and winter, I prefer warm coffee and I find it easiest to grind whole beans myself, prepare a K-cup the night before, and then brew once I arrive. Simple and clean with very little hassle.