On Thu, 16 Feb 2017 15:36:42 +0000, Whiskers wrote:

I use OpenSignal on my Android, in the UK. It currently shows '100
nearby' cell towers on the first page (where your screenshot shows '0
nearby') and they are shown as points on the map within a mile or two of
where I am (in a large busy city). But I'm pretty sure that comes from
the OpenSignal server not from the phone's own hardware.

UPDATE:

I know everyone loves OpenSignal but I prefer an app that provides the
EXACT cellular source when, in my case, it's often a femtocell that is
never going to be on ANY Internet database.

To that end, see this post today on this topic, if it helps others.
o Galaxy S9 in UK - poor signal?
https://groups.google.com/forum/#!topic/comp.mobile.android/0soPAvWzt78


On Sat, 14 Sep 2019 16:32:34 +0000 (UTC), Tony Mountifield wrote:

Ah, I could put my wife's SIM in my old phone to compare...
I do have the OpenSignal app on both.

I agree for cellular you need to be connected to the carrier, which is a
drawback - but luckily you have a second SIM card, where the apps I use can
handle two SIM cards (if the phone can handle two SIM cards of course).

I wouldn't suggest OpenSignal since it's an Internet lookup database which
uses triangulation (last I checked anyway) ... where I'd use one of the
apps in the references that does NOT need any access to the Internet.

I just looked on my phone where I have "Cellular-Z" freeware installed,
which seems to work well to show signal strength in RSSI, RSRP, RSRQ, &
SINR.
https://i.postimg.cc/W4zhW166/cellular01.jpg

In my case, I test femtocell signal and cellular repeater signals, where my
femtocell would never be in an Internet database.
https://i.postimg.cc/TPK3jHft/cellular02.jpg

o Cellular-Z, by JerseyHo
https://play.google.com/store/apps/details?id=make.more.r2d2.cellular_z
"Cellular Z is a telecom signal quality and Wifi network info, channel
info software, the main functions are as follows:
1.Dual SIM mobile phone network information (SIM card serving cell, serving
cell signal quality,neighboring cells).
2.Wifi information (connected, nearby Wifi list, Wifi channel 2.5 and 5
GHz).
3. Current location information GPS Satellites
4. Device information (battery, hardware, system).
5.speedtest.
6.Map track,indoor coverage."