Why the aversion to apps?
I love mechanical gizmos and totally get why a clockwork drive is so seductive even though its ticks and tocks are rarely even.
And for decades I happily fed whole landfills worth of 9 volt batteries into my Dr. Beat with the sliders until I discovered rechargeable li-ions in 9 volt form factor and turned it green.
I agree most apps are total crap. But there are some standouts. Ever since I found Pro Metronome for my Android phone, the good Doctor has been in retirement. The app does all the Doctor could do plus gradually incrementing the tempo for bringing passages up to speed, more choice of subdivisions, and has programmable polyrhythms for those times when you have get used to playing say 5 against someone elses 4. All with a very clean, simple dashboard.
Then throw in a Peterson Tuner App which which has no problem hearing the low B on my 5-string. Several apps which will play chordal drones to help you get your tootsies in the right place on the fingerboard. And then there are the midi and mp3 players with AB looping and speed control to give you your own portable ensemble accompaniment.
To have all that capability in one small device is transformative. Not to mention reducing clutter.
I held out for a long time before getting a smart phone and some addictive aspects of it still bug me. But musically, man I'm not looking back.
If you're adament though, one of the full size Dr. Beats would be my choice. And some rechargeable batteries because they gorge on electricity.