I have a tuner within an arms reach, anywhere that I have guitars in the house.
4 or 5 clip on units, 3 tuners that came with used guitar purchases, the tuning fork that I discovered in the seventies, the first good Boss Tuner (TU12H), others built into a couple of my acoustics, the Guitar Tuna Ap, and a Peterson Stomp Classic Strobe.
My discovery of the tuning fork, changed my life. Everyone in the jam space used to argue that they were in tune. I was the asshole who proved that they (we), weren't. We progressed musically due to proper tuning. I personally began to catch up with my skills as a player, and figuring out the music at hand, the basic chords, bass line, etc., without the aid of others.
I have been promoting the use of tuners with people that I meet, that still don't have one. I have handed out several tuners to new friends. I want them to experience the growth that comes from being in tune.