What is a good employee engagement SaaS tool for mid-size(50+) companies?

We are looking for a a tool for our employees to be aware of work being done in other departments, feel like they’re in the loop, and ask the exec team questions about strategy and execution (may be even anonymously). Slack doesn't cut it, too noisy. Also, post the 40-employee mark, a company meeting hasn't been sufficient.

I’ve looked around but haven’t found something. Would appreciate any recommendations.