You want to use or build Singularity images on a Windows or macOS system or a linux system where you don't want to install Singularity? No problem! Here comes Sinbularity-Docker!
You need to have Docker installed on your system.
Clone this repository using the following command
git clone https://github.com/nr23730/singularity-docker.git
Navigate to the repository folder and build die Docker image
docker build . -t singularitydocker:latest
Copy the singularity file to some place that is covered by your $PATH environment variable.
Now you're ready to rock!
You can use singularity like you would with a real installation. You just type singularity and your desired commands in the command line.
Be aware that only your current working directory will be available in singularity and execution will be limited to noninteractive mode.
singularity run library://sylabsed/examples/lolcow cowsay