create menu in spreadsheet app scrip
function onOpen( ){
// This line calls the SpreadsheetApp and gets its UI
// Or DocumentApp or FormApp.
var ui = SpreadsheetApp.getUi();
//These lines create the menu items and
// tie them to functions we will write in Apps Script
ui.createMenu('Custom Functions')
.addItem('Get Range', 'getRange')
.addSeparator()
.addSubMenu(ui.createMenu('Advanced Options')
.addItem('Get Range Values', 'getRangeValues'))
.addToUi();
}