"Anbox puts the Android operating system into a container, abstracts hardware access and integrates core system services into a GNU/Linux system. Every Android application will be integrated with your operating system like any other native application."
OpenKeychain helps you communicate more privately and securely. It uses high-quality modern encryption to ensure that your messages can be read only by the people you send them to, others can send you messages that only you can read, and these messages can be digitally signed so the people getting them are sure who sent them. OpenKeychain is based on the well established OpenPGP standard making encryption compatible across your devices and operating systems.
" Tor on Android
Tor is available for Android by installing our package named Orbot. Orbot is an application that allows mobile phone users to access the web, instant messaging and email without being monitored or blocked by their mobile internet service provider. Orbot brings the features and functionality of Tor to the Android mobile operating system."
CyanogenMod is an aftermarket firmware for a number of cell phones based on the open-source Android operating system. It offers features not found in the official Android based firmwares of vendors of these cell phones.
"The feature phone reinvented
KaiOS brings smartphone-like functionalities to affordable phones: the KaiStore for apps. Video calls over 4G. Mobile payments through NFC. Even dual-SIM support."
"This is a list of mobile apps developed by Google for its Android operating system. All of these apps are available for free from the Google Play Store, although some may be incompatible with certain devices (even though they may still function from an APK file) and some apps are only available on Pixel and/or Nexus devices. Some of these apps may be pre-installed on some devices, depending upon the device manufacturer and the version of Android. A few, such as Gboard, are not supported on older versions of Android."
Android for your PC
An Open Source OS, based on Android, that incorporates many optimizations, features, and expanded device support. And it is available for just about any Chromebook, Windows/Linux PC or tablet released in the last 4 years"