TeslaUnread
PLEASE NOTE: As of the release of Nova 7 back in 2021, TeslaUnread support has been completely removed from Nova Launcher and will not be available at any point going forward.
TeslaUnread is an alternative provider of numeric badges for Nova Launcher. TeslaUnread attempts to use various unofficial APIs to get unread counts from apps even when they don't have a notification in the notification shade.
Because of it's use of the READ_SMS and READ_CALL_LOG permissions it is no longer welcome on the Google Play Store and has been removed as a feature within Nova Launcher/Nova Launcher Prime itself. You can still download the APK here.