The wiki is lacking in content. You can help by creating a new article. See the maintenance category for more ways to help.
To export the ReferenceTooltips gadget, click on "Download" button, save the downloaded file, go to Special:Import on destination wiki and upload it. Then add the following to MediaWiki:Gadgets-definition page:
You must have appropriate permissions on destination wiki (including the right to edit system messages) and import from file uploads must be enabled.