Ask HN: What are your go to SaaS products for startups/MVPs?

Looking for some inspiration. Ive done a lot of MVPs/Early-stage apps over the years and I tend to lean on the same SaaS portfolio for mails, text gateways, payment etc, but Im sure Ive missed a few valuable additions.

Here's a few I use: Mails: Mailchimp / Mandrill Payment: Paylike Search: Algolia