Transition JIRA issues with Jirio Slack JIRA app
It is easy to transition JIRA issues from Slack with Jirio Slack JIRA app with action buttons. You do not need to remember what transitions are supported in which ticket state, Jirio will suggest you transitions on its own.
Once you click on the Transitions action button, you will be presented a list of transitions. Once clicked on any transition, a ticket will be moved to this state and the list of transitions will be updated to reflect new ticket state.