Sure. Broadly this is the list. Many of these are my go-to's for all my products. Only the Project management, I had to keep trying new things. Most favorite for now is Trello.

Also, I use dokku for deployment, so it's very similar to heroku and uses heroku buildpacks.

Hetzner - Servers.

Helpscout - Customer helpdesk

Google - workspace Email

Github - Source code

Airbrake - Error monitoring

Posthog - Analytics

Shortcut - Project management

Canny - Feedback & Changelog announcement

Stoplight - API documentation

Slack - For app testing

UptimeRobot - Uptime monitoring

MRR - For subscription tracking

Mailgun - Transactional Emails

Reform - One time used for feedback collection

Calendly - Call bookings

Paddle - Payment platform