These are the Android APIs.

See:
Description

Packages

android	Contains the resource classes used by standard Android applications.
android.app	High-level classes encapsulating the overall Android application model.
android.content	Contains classes for accessing and publishing data on the device.
android.content.pm	Contains classes for accessing information about an application package, including information about its activities, permissions, services, signatures, and providers.
android.content.res	Contains classes for accessing application resources, such as raw asset files, colors, drawables, media or other other files in the package, plus important device configuration details (orientation, input types, etc.) that affect how the application may behave.
android.database	Contains classes to explore data returned through a content provider.
android.database.sqlite	Contains the SQLite database management classes that an application would use to manage its own private database.
android.graphics	Provides low level graphics tools such as canvases, color filters, points, and rectangles that let you handle drawing to the screen directly.
android.graphics.drawable	Provides classes to manage a variety of visual elements that are intended for display only, such as bitmaps and gradients.
android.graphics.drawable.shapes	Contains classes for drawing geometric shapes.
android.hardware	Provides support for hardware devices that may not be present on every Android device.
android.location	Classes defining Android location-based and related services.
android.media	Provides classes that manage various media interfaces in audio and video.
android.net	Classes that help with network access, beyond the normal java.net.* APIs.
android.net.http
android.net.wifi	Provides classes to manage Wi-Fi functionality on the device.
android.opengl	Provides OpenGL utilities.
android.os	Provides basic operating system services, message passing, and inter-process communication on the device.
android.preference	Provides classes that manage application preferences and implement the preferences UI.
android.provider	Provides convenience classes to access the content providers supplied by Android.
android.sax	A framework that makes it easy to write efficient and robust SAX handlers.
android.telephony	Provides APIs for monitoring the basic phone information, such as the network type and connection state, plus utilities for manipulating phone number strings.
android.telephony.gsm	Provides APIs for utilizing GSM-specific telephony features, such as text/data/PDU SMS messages.
android.test	A framework for writing Android test cases and suites.
android.test.mock	Utility classes providing stubs or mocks of various Android framework building blocks.
android.test.suitebuilder	Utility classes supporting the test runner classes.
android.test.suitebuilder.annotation
android.text	Provides classes used to render or track text and text spans on the screen.
android.text.method	Provides classes that monitor or modify keypad input.
android.text.style	Provides classes used to view or change the style of a span of text in a View object.
android.text.util	Utilities for converting identifiable text strings into clickable links and creating RFC 822-type message (SMTP) tokens.
android.util	Provides common utility methods such as date/time manipulation, base64 encoders and decoders, string and number conversion methods, and XML utilities.
android.view	Provides classes that expose basic user interface classes that handle screen layout and interaction with the user.
android.view.animation	Provides classes that handle tweened animations.
android.webkit	Provides tools for browsing the web.
android.widget	The widget package contains (mostly visual) UI elements to use on your Application screen.
com.android.internal.util
com.google.android.maps	The maps package allows applications to display and control a Google Map interface.
dalvik.annotation
dalvik.bytecode
dalvik.system
java.awt.font
java.io	Provides input and output facilities by means of streaming, filesystem access and serialization.
java.lang	Provides core classes of the Android environment.
java.lang.annotation	Defines interfaces and exceptions necessary for annotation support.
java.lang.ref
java.lang.reflect
java.math	This package provides arbitrary-precision integers and decimals.
java.net	Provides networking-related functionality, such as streaming and datagram sockets, handling of Internet addresses, and dealing with HTTP requests.
java.nio	Provides buffers that help handling data.
java.nio.channels	Channels provide a way to connect to sources of data such as files, sockets or other structures that allow input and/or output of data.
java.nio.channels.spi	Service-provider classes for nio channels.
java.nio.charset	This package allows translating between bytes and different character sets.
java.nio.charset.spi	Service-provider classe for nio charset.
java.security	This package provides all the classes and all the interfaces needed by Java security framework.
java.security.acl	This package provides all the classes and all the interfaces needed to build Access Control List.
java.security.cert	This package provides all the classes and all the interfaces needed to generate, administer and verify X.509 certificates.
java.security.interfaces	This package provides the interfaces needed to generate: (1) Keys for the RSA asymmetric encryption algorithm using the PKCS#1 standard; (2) Keys for the Digital Signature Algorithm (DSA) specified by FIPS-186; (3) Keys for a generic Elliptic Curve asymmetric encryption algorithm.
java.security.spec	This package provides the classes and interfaces needed to specify keys and parameter for encryption and signing algorithms.
java.sql	Provides a standard interface for accessing SQL-based databases.
java.text	The java.text package allows to uncouple the text in the application from a natural language.
java.util	Provides an extensive set of utility classes.
java.util.concurrent	Utility classes commonly useful in concurrent programming.
java.util.concurrent.atomic	A small toolkit of classes that support lock-free thread-safe programming on single variables.
java.util.concurrent.locks	Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.
java.util.jar	The java.jar package gives access to jar files content.
java.util.logging	This package allows to add logging to any application.
java.util.prefs	Provides a preferences mechanism, that is, a means of writing configuration data (key/value pairs) to a persistent data store and retrieving it from there.
java.util.regex	Provides an implementation of regular expressions, which is useful for matching, searching, and replacing strings based on patterns.
java.util.zip	This package can read and write the standard zip format.
javax.crypto	This package provides the classes and interfaces needed to define encryption algorithm, keys' agreement algorithms and MAC (Message Authentication Code).
javax.crypto.interfaces	This package provides the interfaces needed to implement the Diffie-Hellman (DH) key agreement's algorithm as specified by PKCS#3.
javax.crypto.spec	This package provides the classes and interfaces needed to specify keys and parameter for encryption.
javax.microedition.khronos.egl
javax.microedition.khronos.opengles
javax.net
javax.net.ssl	This package provides all the classes and interfaces needed to implemenet and program the Secure Socket abstraction based on the SSL protocol SSSLv3.0 or TLSv1.2 All the details of the SSL handshake protocol ar card for, and the cipher set with which a client or a server work can be specified.
javax.security.auth	This package provides all the classes and interfaces needed to implemenet and program different methods of users' authentification and role based users' authorization.
javax.security.auth.callback	This package provides all the classes and interfaces needed to interact with the application in order to execute the authentification and authorization processes.
javax.security.auth.login	This package provides a pluggable and stackable authentication system based on ideas and concepts from the Unix-PAM module.
javax.security.auth.x500	This package provides all the classes needed to store X.500 principals and their credentials.
javax.security.cert	This package is provided only for compatibility reasons.
javax.sql	Provides extensions to the standard interface for accessing SQL-based databases.
javax.xml
javax.xml.parsers	Provides facilities for parsing XML documents and building Document Object Model (DOM) trees from them.
junit.framework	The junit test framework.
junit.runner	Utility classes supporting the junit test framework.
org.apache.commons.logging
org.apache.http	The core interfaces and classes of the HTTP components.
org.apache.http.auth	The API for client-side HTTP authentication against a server, commonly referred to as HttpAuth.
org.apache.http.auth.params	Parameters for configuring HttpAuth.
org.apache.http.client	The API for client-side HTTP communication and entry point to the HttpClient module.
org.apache.http.client.entity
org.apache.http.client.methods	Request implementations for the various HTTP methods like GET and POST.
org.apache.http.client.params	Parameters for configuring HttpClient.
org.apache.http.client.protocol	Additional request and response interceptors.
org.apache.http.client.utils	Helpers and utility classes for HttpClient.
org.apache.http.conn	The client-side connection management and handling API at the heart of what is referred to as HttpConn.
org.apache.http.conn.params	Parameters for configuring HttpConn.
org.apache.http.conn.routing	The client-side route representation and tracking API, part of HttpConn.
org.apache.http.conn.scheme
org.apache.http.conn.ssl	TLS/SSL specific parts of the HttpConn API.
org.apache.http.conn.util
org.apache.http.cookie	The API for client-side state management via cookies, commonly referred to as HttpCookie.
org.apache.http.cookie.params	Parameters for configuring HttpCookie.
org.apache.http.entity	Representations for HTTP message entities.
org.apache.http.impl	Default implementations for interfaces in org.apache.http.
org.apache.http.impl.auth
org.apache.http.impl.client
org.apache.http.impl.conn
org.apache.http.impl.conn.tsccm	The implementation of a thread-safe client connection manager.
org.apache.http.impl.cookie
org.apache.http.impl.entity	Default implementations for interfaces in org.apache.http.entity.
org.apache.http.impl.io	Default implementations for interfaces in org.apache.http.io.
org.apache.http.io	The transport layer abstraction of the HTTP components.
org.apache.http.message	A selection of HTTP message implementations.
org.apache.http.params	The parameterization framework for HTTP components.
org.apache.http.protocol	HTTP protocol execution framework.
org.apache.http.util	Mostly utility classes with static helper methods for various purposes.
org.json
org.w3c.dom	Provides the official W3C Java bindings for the Document Object Model, level 2 core.
org.xml.sax	This package provides the core SAX APIs.
org.xml.sax.ext	This package contains interfaces to SAX2 facilities that conformant SAX drivers won't necessarily support.
org.xml.sax.helpers	This package contains "helper" classes, including support for bootstrapping SAX-based applications.
org.xmlpull.v1
org.xmlpull.v1.sax2

These are the Android APIs.