Nebula is multi-platform, therefore the installation is different depending on which type of OS you want to try it on. Your trial is downloaded as a compressed .zip file. It contains the Nebula.jar, .apk and .bin files and the required installation tools for each OS. The DOCUMENTS page has complete installation instructions.
The Nebula.jar file can simply be copied to any Windows, MacOS or Linux platform device. It's complete and ready to run.
The Nebula.apk file must be side-loaded to an Android device version 4.4.2 or greater using the Android Debug Bridge(ADB) tool included in the download.
The Nebula.bin file is for an ESP8266 WiFi module available from online distributors. The file is installed on a module using the Python esptool.py tool included in the download.
The free evaluation download allows you to build a VPN with up to 4 devices and send the demonstration commands between them.