SaaS platform is more of no-code /low code platform for a particular use-case or solution say - Customer Support, CRM, Marketing automation, Email Marketing, Inventory Management, and so on. whereas No code/low code development tools like https://www.outsystems.com, https://www.dronahq.com, https://www.bubble.io, https://www.notion.so, https://www.adalo.com can be utilised to build any of these solutions.