I would like to use Telegram API for Windows Phone 8. Though unlike other platforms, Telegram doesn't provide source code for Windows Phone. This is unfortunate because it creates a lot of problems for those who want to use it. From my research people mention using REST Service to accomplish that. Though no one showed any exact solution for how to accomplish it. I also read about using RPC calls to accomplish it. I don't know how to do that and I would greatly appreciate someone who could explain step by step to how to implement Telegram in ones app. Big Thanks!
If you need to see source code of an app using the Telegram API you should take a look at github.
There are a lot of apps there using this API:
API, Protocol documentation
Documentation for Telegram API is available here: http://core.telegram.org/api
Documentation for MTproto protocol is available here: http://core.telegram.org/mtproto
Take a look at this one https://telegram.org/apps#telegram-for-wp
You can browser their source code there downloading the zip. Unfortunatelly Stackoverflow does not permit we post a step by step walkthrough of using an API.