Daddario PW-CT-26 Rechargable USB Tuner

This tuner by D'Addario is very compact and lightweight. I like how it folds and turns into every possible angle. I own many (!) products by D'Addario and have never been disappointed by that brand. They just seem to make very good products.

As for the accuracy of the tuner I would say that it's very good. Then again, I use every tuner mainly to align my ukuleles with other instruments from the band. I believe, most instruments (guitars, ukuleles, etc.), no matter how poorly or well they are built, need to be tuned by ear in the end for best results. No tuner can replace the trained ear that knows the specific instrument and knows exactly which notes, overtones and harmonies need to align for the perfect tuning.

This is a fantastic tuner for a number of reasons.
-Charging capability just makes sense, no need to deal with annoying little batteries anymore.
-The battery lasts quite a while. I teach Guitar five days a week and use the tuner multiple times a day for myself and for most of my students and the battery will last for at least 4 weeks before even getting to the orange charge warning. Even then it will last for a week before it gets to the red.
-The clip has a two point swivel and a hinge to position the tuner practically any way you need to to get the best view.
-The LED lights are nice and bright, I haven't used the tuner in strong sunlight but I would imagine you would still be able to read the display.

The only one drawback of this tuner versus some others is that there are no preset modes for standard tunings on some popular instruments. Personally I never use those modes as the chromatic mode can do any tuning you want but some beginners find the preset tuning modes useful.

Two words - Rechargeable Battery.
There's nothing worse than having to look for batteries for your tuner right before a gig. This tuner has a built-in rechargeable battery that charges up in no time. The cable comes included, and you can plug it into anything with a USB port.
The battery usually lasts me up to two weeks if I use it every day. You'll probably get better mileage if your guitar can hold tuning for more than one song!
It swivels into literally any position you want it - even the face rotates. The meters are nice and bright, and the buttons feel good and easy to identify by touch in the dark.
The build quality is good but not great. It's not going to shatter if it falls a few times, but I would be careful tossing it in a bag with pedals and other gadgets.
My only negative is that the USB port isn't USB Type-C which means I must remember to carry the dinosaur Micro-USB cable with me.
On the bright side, there's a battery indicator that tells you how much juice you have left, so I turn it on for a second to check before I go for a gig.

Get one or two!