To install FlawStar on a fresh Ubuntu install, run the following commands:

wget https://www.cs.colorado.edu/~xich8622/src/flowstar-2.1.0.tar.gz;
tar xvfz flowstar-2.1.0.tar.gz;
cd flowstar-2.1.0/;
sudo apt install build-essentials \
                 bison++ \
                 libglpk-dev \
                 libgsl-dev \
                 libmpfr-dev;
make all;

You should now have a flowstar executable in flowstar-2.1.0/. You can test that FlowStar is working properly by downloading an example and piping the example file into STDIN:

wget https://www.cs.colorado.edu/~xich8622/benchmarks/neuron.model;
cat neuron.model | ./flowstar