update readme

readme.md

@@ -1,6 +1,8 @@
 # Network Services Settings
 
-This app provides a GUI to change some priviliged Android settings which configure network services. If available, the system API is used; a simple root-shell-wrapper is setup as failover.
+This app provides a GUI to change some privileged Android settings which configure network services. If available, the system API is used (AOSP only allows privileged/system apps access to this API), but a simple root-shell wrapper is available as automatic fail-over.
+
+Since the app changes the configuration used by the OS instead of intercepting requests at runtime, there are no race-conditions. Some ROMs may however use implementations which differ from AOSP, which can cause the changes to not take effect on those ROMs.
 
 ## Settings
 
@@ -10,7 +12,16 @@ Android sends 1 HTTP and 1 HTTPS request each time a network change is detected.
 ### NTP / Network Time
 Android periodically synchronizes the system clock using NTP. The used NTP server can be configured.
 
+## Tested Android Versions
+- Android 9 (tested with AOSP and HavocOS)
+- Android 10 (tested with AOSP, RessurectionRemix and HavocOS)
+
 ## Future Development
 
 - add support for AGPS source
-- catch and redirect NCC requests made by other apps/frameworks (some to play.googleapis.com/generate_204 and www.google.com/gen_204 were observed)
+- redirect NCC requests made by apps, which don't use the systems connectivity manager
+- expand known servers list
+
+## Known Servers List
+
+The app includes a hard-coded list of "known servers" from which the user may choose (manually entering a server, which is not on the list is obviously also possible). The list is not intended as recommendation, but as list of working examples - enabling users to test their ROM before setting up their own servers. If you know of other servers which you would like to see included in a "known servers"-list, please open an issue.