What 'meta' tools do you have at launch

Suppose you're launching a small web app, what tools or services would you have in place?

I'm wondering what the MVP of a launch looks like, in addition to the product itself.

For example:

• Page tracking: SimpleAnalytics/GoogleAnalytics/Hotjar
• Event tracking: Amplitude, Heap
• Email capture: Mailchimp
• Customer Support: Intercom

When launching a product, which tools do you consider essential, and which would you add later, assuming we want to launch as early as possible.