Customize Powershell Prompt Message to Show Current Git branch name

function prompt{
  $p = Split-Path (
     Get-Location
     ) -Leaf

  git branch | foreach{
    if($_ -match "^\*(.*)"){
     $p += " [" + $matches[1] + " ] "
    }
  }

  $p = $p + ">"
  Write-Host $p -NoNewline -ForegroundColor Green
  return " "
}

Add above function in $PROFILE file. Save and Restart Powershell.

Source: http://veerasundar.com/blog/2013/05/customize-powershell-prompt-message/