Componentes interessantes para Desenvolvimento

Repositório para Libs

https://clojars.org/

Projetos free

https://simplemobiletools.github.io/

--- Player de MP3

https://github.com/alexdantas/kure-music-player

https://github.com/jeancsanchez/JcPlayer

---- Player Completo de Musica

https://github.com/naman14/Timber

--- Radio ---

https://github.com/cr5315/shoutcast-android

https://github.com/vagalume/aplicativo-para-radios

https://apiary.io/ (para Apis (Testes e Repositório)

Library Brasileira para validação de Campos

https://github.com/concretesolutions/canarinho

Library do Acra (Sistema para Enviar Erros para o Desenvolvedor)
https://github.com/ACRA/acra

Sistema de acompanhamento de Erros 

https://mint.splunk.com

Host de Git Privado (Free)

https://bitbucket.org/

Analise Tipo o Analyse e Monetização.

y.flurry.com

Tutorial de Compras no APP
http://tutorialandroid.com.br/in-app-billing-compras-dentro-do-aplicativo/

Tutorial de Google Analytics
http://tutorialandroid.com.br/google-analytics/

Tutorial do Ciclo De Vida
http://tutorialandroid.com.br/ciclo-de-vida-activity/

Componentes como o (MaterialDrawer,Android-Iconics e outros)
https://github.com/mikepenz

Lista de componentes do Google 
https://developers.google.com/android/guides/setup#add_google_play_services_to_your_project

Componente de Leitura de Imagens
https://github.com/nostra13/Android-Universal-Image-Loader

Componente de TabbedDialog (Dialog com abas)
https://github.com/ashishbhandari/AndroidTabbedDialog

Componente de AppUpdater
https://github.com/javiersantos/AppUpdater

Componente de MaterialSpinner
https://github.com/ganfra/MaterialSpinner
https://github.com/jaredrummler/Material-Spinner

Componente de  ExpandDrag
https://github.com/alighters/ExpandDragHelper

Componente de Badger
https://github.com/touchao123/android-viewbadger

Componente de GeoIP
https://github.com/seventhmoon/GeoIp-android

Componente que ajunda montar o chat
https://github.com/himanshu-soni/ChatMessageView

Serviço de Push (CGM) Gratuito (parcial)
https://onesignal.com/

Serviço de Hospedagem de Imagem Gratuito (parcial)
https://cloudinary.com

Componente MultiPicker

https://github.com/coomar2841/android-multipicker-library

Dicas de usar o compartilhador padrão.
http://pt.androids.help/q4650

Gera Gradiente
http://gradcolor.com/

Documentação de Layout
http://www.klebermota.eti.br/2011/09/02/suporte-a-multiplas-telas-no-android/

Librarys comuns para projetos
https://commonsware.com/cwac

Library para PullRequest in ListView

https://github.com/erikwt/PullToRefresh-ListView

Library para Anotation Fast developer

https://github.com/excilys/androidannotations

Library paa injection (elimina codigo , simplifica)

https://github.com/codepath/android_guides/wiki/Reducing-View-Boilerplate-with-Butterknife

Library para Retrofit (Exemplos)

https://github.com/codepath/android_guides/wiki/Consuming-APIs-with-Retrofit

Library para ZBar

https://github.com/zxing/zxing

Librray para Integração do Flurry Yahoo AD

https://github.com/flurry/android-AdIntegrationSamples