Just release this December 2019 is ArcGIS Companion v2.5.

ArcGIS Companion is a native mobile app created to complement your ArcGIS (Online or Enterprise) organization. It is simple, intuitive, well-crafter and ready to help with your ArcGIS organization tasks. 

With Companion v2.5, you can now sign-in to Companion with your various accounts, seamlessly switching between your ArcGIS Online, ArcGIS Enterprise, and Public accounts. 

To learn more on what you can and/or what you must do to enjoy Companion, read the blog of Esri’s Nakul Manocha and Sathya Prasad – “What’s new in ArcGIS Companion 2.5 (December 2019)”; or you can read the v2.4 update announcement; or, join the discussion on GeoNet for your comments and questions; or to learn more about ArcGIS Companion, read the Product roadmap. 

Get the app at the Apple Store, Google Play, and/or amazon appstore.