You can extend Sheets with add-ons that build customized workflow improvements, establish connectivity to third-party systems, and integrate your Sheets data. What you can do · Custom functions
Google Apps Script lets you do new and cool things with Google Sheets. You can use Apps Script to add custom menus, dialogs, and sidebars to Google Sheets. Custom functions · Macros · Container-bound Scripts · Use Connected Sheets
Open a document or spreadsheet in the Google Docs or Sheets app. · Tap More · Tap Add-ons. · Tap Get add-ons. · Tap the add-on you want to install. · Tap Install.