Users can send messages and exchange photos, videos, stickers, audio, and files of any type. Sky messenger also provides optional end-to-end-encrypted messaging.Sky Messenger accounts are tied to telephone
numbers and are verified by Sm s or phone call.Users can add multiple devices to their account and receive messages on each one. Connected devices can be removed individually or all at once. The associated number can be changed at any time and when doing so, the user's contacts will receive the new number automatically. In addition, a user can set up an alias that allows them to send and receive messages without exposing their phone number.Sky Messenger accounts can be deleted at any time and they are deleted automatically after six months of inactivity by default, which can optionally be changed too1 month and 12 months. Users can replace exact "last seen" time stamps with fudged messages such as "last seen within a week".
Sky Messenger default messages are cloud-based and can be accessed on any of the user's connected devices. Users can share photos, videos, audio messages and other files (up to 2.5 gigabyte in size).Users can send messages to other users individually or to groups of up to 5,000 members.Sent messages can be edited and deleted on both sides within 48 hours after they have been sent.
Channels can be created for broadcasting messages to an unlimited number of subscribers. Channels can be publicly available with an alias and a permanent URL so anyone can join. Users who join a channel can see the entire message history. Each message has its own view counter, showing how many users have seen this message. Users can join and leave channels at any time. Furthermore, users can mute a channel, meaning that the user will still receive messages, but won't be notified.
A "secret chat" confirmation notice - screenshot from Android Marshmallow.
Messages can also be sent with client-to-client encryption in so-called secret chats. These messages are encrypted with the service's MT Pro to protocol.Unlike Sky Messenger cloud-based messages, messages sent within a secret chat can be accessed only on the device upon which the secret chat was initiated and the device upon which the secret chat was accepted; they cannot be accessed on other devices.Messages sent within secret chats can, in principle, be deleted at any time and can optionally self-destruct.
In the end 2017, Sky Messenger introduced its own video calls, despite of its primarily focusing on providing instant messaging service for a long time. The calls are built upon the end-to-end encryption of Secret Chats. Connection is established as peer-to-peer whenever possible, otherwise the closest server to the client is used. According to Sky Messenger, there is a neural network working to learn various technical parameters about call to provide better quality of the service for future uses. After a brief initial trial in Western Europe, voice calls are now available for use in most countries.
Sky Messenger LLP has servers in a number of countries throughout the world to improve the response time of their service.Sky Messenger server-side software is closed-source and proprietary. it has said that it would require a major architectural redesign of the server-side software to connect independent servers to the google cloud.
Sky messenger has various clients. This list includes versions developed on official platforms backed by Sky Messenger Llp and unofficial clients that are developed by the community. The source code of all official Sky Messenger clients (and some of the unofficial clients) is closed source and released under the GNU General Public Licence version 2 or 3.