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Smarter Contact is a cloud-based CRM and marketing automation platform that helps businesses engage and nurture leads, measure campaign performance, and manage sales to accelerate deal closures. The service is offered via a subscription model and advertises a free trial.

iMessage is Apple's instant messaging service and protocol, integrated into the Messages app on iOS, iPadOS, watchOS and macOS. It supports end-to-end encrypted text, photos, video, reactions, and other rich content between Apple devices and falls back to SMS/MMS when messaging non-Apple phones.

BlueFerry is experimental Linux software that connects a paired iPhone to a Linux desktop over Bluetooth, without a Mac relay, Apple login, cloud service, or subscription. It provides native GTK, KDE/Kirigami, Quickshell, and terminal clients for reading and sending SMS, RCS, and iMessage, starting conversations, syncing contacts, marking messages read, and optionally mirroring other iPhone notifications. Local message history can be encrypted with GNOME Keyring or KDE Wallet. It only receives messages observed while connected and does not download an iCloud Messages archive. Attachments, reactions, typing indicators, FaceTime, calls, and complete sent-message history are unsupported; group replies are disabled or require confirmation when Bluetooth does not provide enough participant information. The project distributes native packages for several Linux distributions and warns that changes to iPhone Bluetooth behavior could affect compatibility.

SendGrid is an email API and email marketing campaigns platform from Twilio. It sends transactional messages such as waiver copies and organizer alert emails.

Slybroadcast is a company that provides ringless voicemail drop services and voicemail messaging software for businesses. Its platform enables users to deliver prerecorded voicemail messages directly to recipients' voicemail inboxes without initiating a phone call.