Gnome Shell Extension Inhibit Applet is a gnome shell extension that gives you the ability to inhibit auto-suspend or screensaver from activating, simular to the original applet in gnome 2. It will place a switch in the power menu if it's available, and the a11y menu if not. If the power menu isn't available and the Remove Accessibility extension is enabled, it will place it in the status/user menu.
This was forked from Raphael Kimmig's Gnome-Presentation-Mode, in hopes to improve it and add more translations. I don't take an credit for the work that he has done on this extension so far.
Go onto https://extensions.gnome.org and find the extension. It's much easier to install it through that website than manually. If you wish to install it manually, just copy the "[email protected]" folder into: ~/.local/share/gnome-shell/extensions
Copyright (C) 2012, Jeremy Newton and Copyright (C) 2011, Raphael Kimmig
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA