ZapZap is a messaging app, based on the source code of the Official Telegram (https://github.com/DrKLO/Telegram), with a focus on speed and security. It’s superfast, simple and free.
This repo contains official ZapZap App for Android source code.
Documentation for Telegram API is available here: http://core.telegram.org/api
Documentation for MTproto protocol is available here: http://core.telegram.org/mtproto
Import the root folder into your IDE (tested on Android Studio), then run project.