GrowERP is a multi company business development platform using a Flutter front-end and the Moqui open source ERP system as back-end. It can also be relatively easy adapted to other back-end systems like the Apache OFbiz system for which a proof of concept is available.
Being an end user, GrowERP is available as a SAAS application which can help you to smoothly operate a business, or as a system integrator/programmer to provide flexible business applications to your end-users. In general the system is targeted at the mid/small size businesses and one man operations.
The system is open source and is available at the Github platform in a single repository.
We have an email mailing list to keep you informed about the system, Flutter and about ERP in general.