Good coyote call ?

Predator Quest is a TV show usually on Friday nights around 19:00. Here is the website....https://www.predatorquest.com/

They have hand calls but they normally use a "Lucky Duck" electronic call on the show. Works very well. Since its one of their sponsors you need to look for that sponsor on the website. Electric are from 4150 up. hand calls are less than $60 from what I recall.

Good luck!

mike 
 
In your price range, the Primos Alpha Dog is as good as it gets. Color display, powerful ( make sure you have good batteries), speakers can be aimed, pre-programmed hunts (sequences) included, and you can add your own hunting sequences. I owned one in the past. Hand calls are always necessary as a backup, but nothing will get you to success fastr than getting the sound away from you.
 
Agree with the Primos. I have one and it works well and is very easy to use. Just make sure to always have good batteries!

Not sure how I would feel about a phone app electronic call. Unless there is another piece of hardware involved I doubt it would be loud enough for many situations. Also would assume that the phone would be on/with you, the shooter, and generally you don’t want the target to be fixating on you and your location. You want them looking at something else, hence the reason for electronic calls with remote controls. 
 
You could connect to a remote speaker with WiFi or Bluetooth. I had no idea they were around until a young man I know who hunts strictly with a bow including calling coyotes uses it. Of course if he isn't bow hunting he's playing with his phone so it's only natural for him.

Me I've personally never personally used calls other than for Elk although I have a few predator and a turkey call laying around