Outfound has no separate iOS or Android app. It is web-based; you sign in from the browser on your computer or phone.
The interface adapts to phone screens: the menu collapses, tables turn into rows and actions open in bottom panels. Reading replies, changing stages in the CRM or checking a discovery's progress work comfortably on a phone.
For setting up campaigns, adding DNS records or working with large results tables, a computer is recommended. Drag and drop on the pipeline board is off on narrow screens; change the stage from the person's details instead.