Instructions say to run:

yarn && yarn test

I get:

$ yarn test
yarn run v1.22.4
warning package.json: No license field
error Command "test" not found.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

package.json seems to lack a test command.

I believe xstateful could have more integrated devtools in the future, but for now, there is a quick and easy devtools integration.

I believe Redux Devtools could be setup to display both state and xstate, along with all actions fired.

As an example of how Redux Devtools can be setup for use with xstate, see React-Automata:
https://github.com

The 'simple routing' example on codesandbox referenced in the README doesn't work, loading stops with a 'module not found' error.