Persistent call detection on iOS - ios

Question

I have written an Android application which, even after termination, still runs a service that listens for phone state transitions. This way, the application was able to detect new phone calls and trigger a certain event, for example the dialog partner's number was stored in a database.
Now I am eager to implement this application on iOS as well, but I cannot figure out if it is even possible to listen for phone calls in a similar way. For all I know so far about iOS, whenever my application is terminated by either the user or the OS, it is not possible anymore to detect new phone calls.
Is there any way I can achieve this, or have I already reached a dead end?
EDIT: As it was said to be too broad:
I want to detect both incoming and outgoing calls at any time. It there a way to do this on iOS 10? I do not want code, I just want to know if it is possible.

Answer 1

Please investigate further App Sandbox principe that Apple is using.
In short:
App Sandbox is Based on a Few Straightforward Principles By limiting
access to sensitive resources on a per-app basis, App Sandbox provides
a last line of defense against the theft, corruption, or deletion of
user data, or the hijacking of system hardware, if an attacker
successfully exploits security holes in your app. For example, a
sandboxed app must explicitly state its intent to use any of the
following resources using entitlements:
Hardware (Camera, Microphone, USB, Printer) Network Connections
(Inbound or Outbound) App Data (Calendar, Location, Contacts) User
Files (Downloads, Pictures, Music, Movies, User Selected Files) Access
to any resource not explicitly requested in the project definition is
rejected by the system at run time. If you are writing a sketch app,
for example, and you know your app will never need access to the
microphone, you simply don’t ask for access, and the system knows to
reject any attempt your (perhaps compromised) app makes to use it.
On the other hand, a sandboxed app has access to the specific
resources you request, allows users to expand the sandbox by
performing typical actions in the usual way (such as drag and drop),
and can automatically perform many additional actions deemed safe,
including:
Invoking Services from the Services menu Reading most world readable
system files Opening files chosen by the user The elements of App
Sandbox are entitlements, container directories, user-determined
permissions, privilege separation, and kernel enforcement. Working
together, these prevent an app from accessing more of the system than
is necessary to get its job done.