An asynchronous callback-based Http client for Android built on top of Apache’s HttpClient libraries. All requests are made outside of your app’s main UI thread, but any callback logic will be executed on the same thread as the callback was created using Android’s Handler message passing. You can also use it in Service or background thread, library will automatically recognize in which context is ran.

The Apache Commons Codec package contains simple encoder and decoders for various formats such as Base64 and Hexadecimal. In addition to these widely used encoders and decoders, the codec package also maintains a collection of phonetic encoding utilities.

Apache Cordova is a platform for building native mobile applications using HTML, CSS and JavaScript.

The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms, it was developed by the Legion of the Bouncy Castle. The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework. The Bouncy Castle Crypto APIs for Java consist of the following: A lightweight cryptography API. A provider for the Java Cryptography Extension and the Java Cryptography Architecture. A clean room implementation of the JCE 1.2.1. A library for reading and writing encoded ASN.1 objects. Lightweight APIs for TLS (RFC 2246, RFC 4346) and DTLS (RFC 4347). Generators for Version 1 and Version 3 X.509 certificates, Version 2 CRLs, and PKCS12 files. Generators for Version 2 X.509 attribute certificates. Generators/Processors for S/MIME and CMS (PKCS7/RFC 3852). Generators/Processors for OCSP (RFC 2560). Generators/Processors for TSP (RFC 3161 & RFC 5544). Generators/Processors for CMP and CRMF (RFC 4210 & RFC 4211). Generators/Processors for OpenPGP (RFC 4880). Generators/Processors for Extended Access Control (EAC). Generators/Processors for Data Validation and Certification Server (DVCS) - RFC 3029. Generators/Processors for DNS-based Authentication of Named Entities (DANE). Signed jar versions suitable for JDK 1.4-1.8 and the Sun JCE. The lightweight API works with everything from the J2ME to the JDK 1.8 and we now provide certificate generation, PKCS/CMS/CRMF/CMP/EAC/DANE/DVCS/TSP/TLS/DTLS and OpenPGP support across the full range of JDKs.

Deprecated Google Cloud Messaging for Android (GCM) is a service that allows you to send data from your server to your users' Android-powered device, and also to receive messages from devices on the same connection. The GCM service handles all aspects of queueing of messages and delivery to the target Android application running on the target device. GCM is completely free no matter how big your messaging needs are, and there are no quotas.

Guava is a set of core Java libraries from Google that includes new collection types (such as multimap and multiset), immutable collections, a graph library, and utilities for concurrency, I/O, hashing, caching, primitives, strings, and more! It is widely used on most Java projects within Google, and widely used by many other companies as well.

JSON processor (JSON parser + JSON generator).

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