Best practices to improve the SEO for a Meteor application?

By searching on Hashnode for the best practices to make a meteor app SEO-friendly, I found out this article, but it didn't help me a lot, since I'm searching something free-forever for this kind of thing.

So, I wanted to ask you what are the best practices to improve the SEO for a Meteor application. And another question: is it really necessary, or has google improved its spider and now it should index my pages even without any improvement? I'm asking because there are several websites, like 500px (500px.com), that are made with backbone, apparently without any improvement (try to disable js and it won't load the website), while the SEO is great as well.

Thank you in advance for your help.