As a point of context, developing for watchOS is brutally difficult and soul-crushingly frustrating. Wireless debugging from Xcode is slow and unreliable. All of the watchOS frameworks are hard to use and badly documented. Much of the system is nondeterministic in unexpected ways, which makes testing obnoxiously difficult. One developer I know has special server code to upload custom logs from only watches on their user account, because shipping logs to a server is more reliable than the Xcode debugger.
Although I'd also love to see a standalone watchOS app, I fully expect that we won't see one until Apple makes watchOS development less painful. Telegram barely fixes bugs in their major applications; I can't imagine they have time to burn on watchOS development.