Under Labs (the development side of things) there used to be a tool called “Fetch as Googlebot“. This went away and showed you what Google saw for any particular page on your site (you have to wait some time for the results – it is not instant for good reason). This has now grown up and moved to Diagnostics.
It has also added the ability, having ‘fetched as Googlebot’, to submit a page (or a tree of pages) to Google for indexing. OK Google isn’t going to drop everything to instantly re-index the page you ask it to do this for, but if you’ve made major updates to a key page then it’s a simple way of giving Google a nudge to have a look at it as soon as it can (a lot simpler than other tricks we might bring to bear to try to achieve the same thing).