How to get alerts about Speed Monitoring Cameras in GPS Maps Application? I am using Here Maps (Here WeGO), but I do not get any warnings about speed monitoring cameras. 
I would also like to pay for such a service. 
The application well informs already if you drive too fast. 

I know there are some GPS devices which can give such alerts. 
I think TomTom, at least. 

Testing xavier_fakerat's proposal

I see now interaction with CamerAlert but have not tested when driven. 
It took some time for the program to relocate to Baltics from London. But


Start here maps. Start then CamerAlert second time. The app crashes. It alerts all the time about unupdated maps although I just updated them. 


I will go with Sygic. 

OS: Android Oreo 8.0
Phone: OnePlus 3T
Region: Sweden, Finland, Norway, Baltics
Maps: Here We Go Maps, rarely Google Maps (because no easy offline use)
You may need an additional tool for Speed Camera alerts or an alternative navigation tool with built-in speed cam alerts feature.
For the former, there are  some options from playstore but ideally you'd still want to keep Here WeGo so you could go for an application with an overlay support/widget that ensures you use your primary navigation app whilst still getting speed cam alerts in the background.
A few options present:
CamerAlert (from PocketGPSWorld) for a very up-to-date speed camera database; it is updated at least weekly and includes mobile sites. It can be used as an overlay with any navigation app.

CamerAlert is a self-contained Speed and Red Light Camera warning
system using data from the renowned PocketGPSWorld.com Speed Camera
Database.
It provides both audible and visual warnings as you
approach a camera. Uniquely, when you are in a section of SPECs
(Average Speed) cameras, CamerAlert displays your average speed
between each camera in the zone.
CamerAlert also utilises directional
information to reduce the number of &quot;False Alerts&quot;, you are only
warned for cameras that monitor your direction of travel.

Costs:

PocketGPSWorld subscribers can use their annual membership to keep the
camera data up to date by linking their member details in the app.
If you are not an existing subscriber you can subscribe in the app to
ensure access the our regular updates. A subscription can be used on
other GPS devices as well as the Android (maximum of three devices,
one of which may be an Android or iPhone SmartPhone).
An annual subscription costs £19.99

Learn more at the official website

Alternatively running other navigation apps' camera alerts application is worth a try, Sygic Speed Cameras &amp; Traffic or TomTom Speed Cameras also serve similar purposes with the latter with overlay support.
Sygic:


offline database of more than 50 000 fixed speed cameras, average
speed checks and red light cameras in your app.

with Speed Camera's Premium, you can see your current speed, speed limits, and warnings also in other apps (Paid feature)



Pricing see here

Tom tom speed cam app, see here to learn more.
Also worth noting is that the regions in question are covered by these tools.