Drone / tuning fork app recommendations

[TomInME]

Any recommendations for an app that will generate a drone or tuning fork tone for use practicing scales and whatnot? I feel pretty in tune with myself but run into issues with other instruments/players sometimes, and would like to be more sure about where I'm at.

Alternate: a tuner would also be fine but I have yet to find one that is more than barely acceptable for trigger notes and pedals.

Adding a mic is something I would consider, if it makes a significant difference.

[norbie2018]

https://www.dronetonetool.com/

[timothy42b]

Try Cello Drones from youtube.

[marccromme]

Try Cello Drones from youtube.

[Rusty]

The Tonal Energy Tuner app is great - tuner, metronome and a whole bunch of sound analysis tools in the same app. You can stack notes on top of one another to build chords/drones.

[TomInME]

https://www.dronetonetool.com/

That's about as easy as possible - thanks!