I'll start! I invested in a cordless vacuum, primarily because it came with a pet hair accessory but turns out, I love to use it for a quick dopamine hit! Getting a room or two to look clean-ish without the commitment of finding an outlet and dragging a chunky vaccum across the room is a massive help!
Imagine my displeasure at having to shower without a shower curtain for 2 years. Never bothered to put one up bc I didn't think I'd live in this apartment for this long... I hate every minute of showering in the winter.
(Also, it's not an ADHD thing in my case, the bathroom is a weird shape that doesn't allow for a simple rod and curtain, I'd have to get a semi custom glass wall installed)