Tohu
Ko te Waitohu he ratonga karere whakamunatia-whakamuna i hangaia e te Signal Foundation me Signal Messenger LLC. Ka whakamahi i te Ipurangi ki te tuku karere kotahi-ki-tetahi me te roopu roopu, ka taea te whakauru i nga konae, reo tuhipoka, whakaahua me nga ataata. Ka taea hoki e ona taupānga pūkoro te waea reo me te waea ataata kotahi-ki-tetahi, a ka taea e te putanga Android te mahi hei taupānga SMS.
Ka whakamahia e te Waitohu nga nama waea pūkoro paerewa hei tautohu me te whakamahi i te whakamunatanga mutunga-ki-mutunga ki te whakapumau i nga korero katoa ki etahi atu kaiwhakamahi Waitohu. Kei roto i nga taupānga nga tikanga e taea ai e nga kaiwhakamahi te manatoko takitahi te tuakiri o o raatau hoapaki me te pono o te hongere raraunga.
All Signal software is free and open-source. The clients are published under the GPLv3 license, while the server code is published under the AGPLv3 license.
Yes having a phone number in order to register an account is a trade. Else Signal is completely trade-free and a fantastic alternative for Whatsapp (which belongs to I-collect-everything-about-you-and-sell-it-to-advertisers-Facebook).
Signal requires you to have a mobile phone number in order to register an account with them. For that matter I do not see it as fully trade-free.