WordPress web site in maintenance or lauching page

You want to put your WorPress web site on maintenance mode or create a single lauch page: follow the guide.

On most CRM, this function is native, with WordPress you will have to add a plugin.

For maintenance mode, you can get by using the native maintenance page, but you will be better off using a plugin.

It's all detailled on the french version of the article, ask for a translation in the comments if needed.