Zadarma
Zadarma Project
Hushed - 두 번째 전화번호
AffinityClick Inc.
Linphone
Belledonne communications
Zadarma Сonf - бесплатные виде
Zoiper IAX SIP VOIP Softphone
Securax EOOD
Zello PTT Walkie Talkie
Zello Inc
Threema. The Secure Messenger
Threema GmbH
RingCentral
Talkatone: Texting & Calling
Talkatone, Llc
Textra SMS
Delicious