As you may know, Telegram is already available on Ubuntu Desktop.
A month from now, Telegram 2.0, based on TelegramQML developed by Aseman will be implemented on Ubuntu Touch. It will be built on Cutegram, which is an open-source telegram client.
As a reminder, Ubuntu Touch is a stable operating system, but it is not mature enough, compared to Android and iOS. For now, there are three Ubuntu Phones: Bq Aquaris E5 HD, Bq Aquaris E4.5, Meizu MX4, but the system is also officially supported on the LG Nexus 4 device.