Alternativas ao OneSignal para PHP com licença de código aberto

• PHP
  Todas as plataformas Windows Mac Linux Chrome OS Android iPhone Windows Phone Blackberry Apple Watch Android Wear iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) Firefox Opera Safari Internet Explorer PHP Windows Mobile Wordpress Shopify Apple TV Chrome Joomla Magento Community Edition .NET Framework Amazon Web Services WiX.com Android SDK Heroku IBM Bluemix Firebase AWS Mobile Hub Google Tag Manager Appcelerator Urban Airship Parse Server Parse deployd NodeChef Backendless Pusher
• Licença Open Source
  Qualquer licença Licença gratuita Licença Open Source Licença comercial