Blink is an easy to use multimedia SIP client. * OSX Integration (iCloud, iTunes, Address Book, Keychain, Voice Over) * Clear audio using Opus codec optimised for full spectrum audio * Telephony compatible codecs * Video calls * Acoustic echo cancelation * Presence (SIP SIMPLE RLS and XCAP protocols) * Chat and File Transfers sessions (MSRP protocol) * Instant Messaging (SIP Message) * Screen Sharing (VNC protocol) * Multiparty conferencing (audio, chat and file transfers) * End-to-end chat encryption (OTR protocol) * End-to-end audio encryption (ZRTP protocol) * Corporate directory services (LDAP protocol) * OpenPGP support for SIP messaging * Compatible with telephony applications (dialpad, call hold, call transfer) * Fine-grained settings for SIP experts Blink does not collect any data. Contacts accessed by Blink from system address-book are not uploaded to any servers.