My great scanner is in the next room.  It’s a Bearcat 800 XLT - receiving VHF-Low, VHF-High, UHF, and aircraft band.  I got it for $40-$50 from eBay.
   It scans either 20 or 40 channels - as chosen by user.  If you only are using 20 or less, it scans them faster if set for 20.
   I programmed it with the local police, volunteer fire, EMT - and local aircraft - channels.  I also put in area ham-radio frequencies - including the favored nonrepeater ones.  That worked fine - until the local police went to 800 MHz digital; though it receives 800 MHz, it doesn’t receive digital.  However, anything serious gets rapidly onto the ham-radio channels - sometimes before the “official” police channels.  It thus gets a lot that the scanner app on a smartphone can’t.
   I plugged it into a magnetic-mount antenna atop my “ground plane” - a radiator by the window.  Reception is great.
   Downside?  Well, the display is hard to read - unlike earlier Bearcat scanners which had displays you could read from anywhere in the room.  And squelch gets “buggy” at times - apparently when a storm is in the area.

Bearcat 800 XLT scanner.