Gravity is a SaaS boilerplate for Node.js & React that enables developers to spin up a new SaaS product in 5 minutes, instead of 5 months.

Save time and money by deploying common SaaS features in minutes, freeing up time and resources to develop value-driven features that customers will pay for.

Gravity contains every SaaS feature you need in a single install:

1. Subscription payments
2. React UI
3. Users & Secure Authentication
4. Social Sign-ons
5. REST API
6. MySQL, Mongo, Postgres, SQLite support
7. Teams/Organisations
8. Email Notifications
9. User Management
10. Integration Tests
11. Security & Permissions
12. User Feedback
13. User Onboarding
14. User Impersonation
15. Error Logging
16. Slack Community

InboxStack is an email deliverability intelligence platform built for teams who need to know why their emails aren't reaching the inbox — not just that they aren't. At its core is Brain, a proprietary causal AI engine trained on a 22-year deliverability knowledge base, which correlates signals across your ESP, DNS authentication records (SPF, DKIM, DMARC), Google Postmaster Tools, Microsoft SNDS, and 50+ blocklists to pinpoint root causes instead of surfacing raw metrics.

Most deliverability tools stop at monitoring: they show you a drop in inbox placement or a blocklist hit and leave you to investigate. InboxStack goes further, tracing the actual causal chain — a DKIM misalignment, a reputation dip on a specific sending IP, a content trigger — so you can fix the real problem instead of guessing.

Setup takes minutes with no migration required: forward your email headers for an instant DNS/authentication audit, or connect your existing ESP and Postmaster accounts for ongoing monitoring. Optional seed testing gives you real inbox-vs-spam placement data across major providers.

Built for agencies managing multiple client domains and growing companies who've outgrown basic authentication checkers, InboxStack turns deliverability from a black box into a diagnosable, fixable system.