Retool is focused more on visual builders and requires more configurations/code to set everything up via custom dashboards.

Motor Admin has a simple unified Admin UI without the need of actually building the UIs unlike in Retool WYSIWYG.

The versatility of Motor Admin can be achieved via in-app UI configurations, custom forms, reports, and dashboards.

Btw, here is a short demo: https://www.youtube.com/watch?v=ZD4Six8ZEP8

Also, Motor Admin has a simple self-hosted deployment option.

Or ForestAdmin

The biggest difference is that Motor Admin has a convenient self-hosted option with a single click deploy. Self-hosted comes with many benefits like custom domain, ability to host under VPN, and faster UI due to lower network roundtrip and CORS avoidance.

Also, Motor Admin open-source version has powerful business intelligence features with custom SQL reports, BI dashboards with variables and fields, and automated email reports.

Also Motor Admin's UI is optimized on mobile and the UI is faster in general.

In terms of available features open-source, self-hosted Motor Admin could become a much better option than ForestAdmin SaaS for an admin interface.