Yes, the Android layer can run Whatsapp and Signal. I also run Firefox as an apk on it, I use the last v68 version of that. The Android layer is only available

Yes, the Android layer can run Whatsapp and Signal. I also run Firefox as an apk on it, I use the last v68 version of that. The Android layer is only available on the commercial version, and only on officially supported device. It has been available since 2013 on the original Jolla 1, which was for me the reason to upgrade from a Nokia N9. For me it is stable on my XA2. Though the software is made by a small company and their efforts are spread relatively thin. They don't have thousands of developers working on their mobile OS. For Android apps, the bluetooth stack of Android and Linux/Bluez is different, and the middleware called libhybris does not support offering bluetooth to Android apps. It might come in the future, many people in the community wish it to come available. There are many native apps, and there might not be that much need for all kinds of Android apps. Also, there is talk about offering Android support for community devices, like the Sony Tama devices (high end, small form factor) or Xiaumi devices.