RoboKiller never interferes with outgoing calls, regardless of iOS version. Outgoing calls are always managed by the native iOS Phone app. When dialing a number from the RoboKiller app, the call is placed and handled fully with the native iOS Phone app.
RoboKiller uses a combination of carrier network (PSTN) and Voice over IP (VoIP) to deliver calls to your phone. The technology and how calls are received on your phone are determined by the iOS version the device is running when RoboKiller is set up. If you upgrade your iOS version, it is recommended that you disable/deprogram your phone, uninstall, and reinstall RoboKiller to ensure you have the best experience. You can find instructions on how to disable/deprogram RoboKiller in the Settings menu of the RoboKiller app.
Silence Unknown Callers (SUC)
Silence Unknown Callers (SUC) is a new feature for iOS 13 that, when enabled, will send any non-contact call to voicemail automatically. Siri Intelligence may allow phone numbers you have texted or phone numbers that are in your emails to ring through. If an emergency call is placed, SUC will be temporarily disabled for the next 24 hours to allow for your iPhone to be reached. For more information see this Apple Support Article.
VoIP Call Quality
Call quality for calls handled by RoboKiller may be impacted more significantly by network conditions and signal strength than calls handled by the traditional carrier network. We are constantly monitoring call quality metrics and are looking at improvements whenever possible.
Conditional Call Forwarding (CCF)
Users with phone carriers that support Conditional Call Forwarding (CCF) will configure their phones’ using a combination of iOS Silence Unknown Callers feature and CCF. This setup provides users with the best possible calling experience since all incoming calls from contacts or numbers identified by Siri Intelligence are over the PSTN. Screened callers, as well as numbers RoboKiller is highly confident in as legitimate calls, are forwarded back to the app using end-to-end encrypted VoIP. In order to have the best calling experience, it is recommended that you add any numbers you will talk to frequently to your contacts.
Unconditional Call Forwarding (UCF)
Users with certain phone carriers, which do not support CCF will configure RoboKiller using Unconditional Call Forwarding (UCF). Under UCF, all incoming calls are redirected to RoboKiller, before your phone rings, and then safe calls are forwarded back to the app using end-to-end encrypted VoIP.