Anything that removes friction from getting you to consistently strength train with progressive overload will do more for your health, quality of life, and appearance than damn near any other possible intervention.

A squat rack, weights, and a bench is probably the biggest bang for your buck version of this and if you can set up a basic home gym, it's a total game changer.

My partner got me a $35 pullup bar, and that has significantly improved my fitness.

A Waterpik also is great as a tiny pressure washer to clean things in the kitchen or bathroom that might give you problems.

For example there are places around my sink drain that are hard to clean by hand. A blast from the Waterpik on the full setting easily deals with them.