Third-party components and resources

TDLib: used for interacting with Telegram API and caching data

LevelDB: used for storing local data and settings

libtgvoip & java layer by the same author: used for VoIP

rlottie: fork of Samsung library, used for animated stickers

lz4: used for storing cached frames of animated stickers

WebP: used for showing static stickers on Android versions below 4.4

ExoPlayer: used for audio and video playback on supported devices

libvpx: vp9 ExoPlayer extension

flac: flac ExoPlayer extension

ffmpeg: used for GIF playback & ffmpeg ExoPlayer extension

libyuv: used to convert pixel format while decoding GIFs

opus: used for voice messages

opusfile

ogg

AndroidX: various basic Android stuff + CameraX

Play Core: used for in-app update system

Google Play Services: maps and location services

Firebase Messaging: notifications

YouTube: YouTube player API

Transcoder: used to compress video files

ShortcutBadger: used to show badge near app shortcut

ReLinker: used to properly load native shared libraries

Konfetti: confetti animation

ZXing: QR scanning on devices where Google Play Services are not available

Google's Material Icons: most of application icons

Material Design Icons: various icons by Austin Andrews, Yasmina Lembachar, Haley Halcyon, Michael Richins

Klaxon: JSON parser used in build scripts

Diff-Match-Patch: source code

RTL View Pager: source code

svg-android: source code