Alternatives to Rattle

Party on Slack

Communication

Strongest fit on feature parity. The most direct functional swap. Shares communication feature signature, comparable workflows, and a similar audit-score band — switch costs are usually lowest here.

GreetBot

Communication

Wider scope, slightly different focus. Wider feature surface than the source app's focus area. Useful if you're shopping communication alongside adjacent capabilities you'd otherwise integrate separately.

15Five

Communication

Established alternative with audit-grade listing. Established option with the rating + review depth to be vendor-evaluated. Best when running this category at scale and you can't afford early-stage product surprises.