Web Design
WordPress is probably the most well known web development platform. Webflow is relatively new, but one I have fully embraced.
Adobe XD is my tool of choice for wireframing and prototyping, and Dreamweaver still has a place too.
E-Commerce
Stripe is a relatively new online payments processing platform, and WooCommerce is a popular e-commerce solution for WordPress websites.
SagePay and Paypal are widely recognised payment processing options.
SEO & Marketing
Mailchimp is a widely used email marketing tool, great for newsletters and lead generation campaigns.
Google tools enable you to keep track of site traffic, and promote your site in their search results. SEMrush is an excellent SEO tool to aid keyword research.