Run the following to create ~/.git-completion.bash:

curl https://github.com/git/git/raw/master/contrib/completion/git-completion.bash > ~/.git-completion.bash

Then add the following to your ~/.bashrc or ~/.bash_profile after PATH:

# Set the base PS1
export PS1="\t: \W$ "

# Source the git bash completion file
if [ -f ~/.git-completion.bash ]; then
    source ~/.git-completion.bash
    GIT_PS1_SHOWDIRTYSTATE=true
    GIT_PS1_SHOWSTASHSTATE=true
    GIT_PS1_SHOWUPSTREAM="auto"
    PS1='\t:\[\033[32m\]$(__git_ps1 " (%s)")\[\033[00m\] \W$ '
fi

export PS1

This will display the branch name next to the folder name in the bash prompt.

Symbols after the branch name indicate additional information about the repo state:

• *: The branch has modifications
• $: There are stashed changes
• =: The branch is equal with the remote branch
• <: The branch is behind the remote branch (can be fast-forwarded)
• >: The branch is ahead of the remote branch (remote branch can be fast-forwarded)
• <>: The branch and remote branch have diverged (will need merge)