Slack is a business app thats available on iOS and Android mobile devices. It’s a app that helps teams communicate better. It’s also available online via browser. It can be used to message your team regarding projects, topics, meetings, etc. One feature is that you can call a person and/or a group in your team. Slack also allows documents to be shared and viewed to all people in your slack.
For people who dread working in groups/teams, this app will make you be up to date with your members. Can message them through the app and will appear on your teammates mobile device/browser instantly. No need to give away personal phone numbers or your Facebook.