This is a short procedure to build genapp from sources:
export GOPATH=~/go # Set the go path
mkdir ~/go/src && cd ~/go/src # Create src folder and enter in it
git clone git@github.com:forj-oss/goforjj.git # Clone goforjj repository
cd /goforjj/genapp # Enter in genapp folder
source ./build-env.sh # Source environment
build.sh # Build
go install # Now you have genapp build on ~/go/bin