Freedom to choose your preferred app interface
Web interface 
Use the Ottspott webapp to manage your team settings, number & voicemail preferences, set Slack notifications but also to access all your call data.
If you are using the free Slack plan, this can be very useful as Slack limits your access to older data.
(web, desktop, mobile)
Use any Slack app to access your Ottspott number(s), channel(s), control the Ottspott bot, make and receive calls, launch bot and slash commands. You will be notified only on what you have set on the Ottspott web app.
The Slack mobile app will also allow you to call back contacts, listen to voice mails and get transcriptions if you are away from your desk or in a meeting.
Desktop app
If you have a more intense use of phone, you can use the Ottspott Desktop app to make and receive calls.
Use the caller ID you want to display the number you wish, access the Slack call feed and label calls so that your team members can take actions.