Modern web UI is nice, but at the end of the day when it comes to mobile, apps are still king.
If the purpose of this is to replace the interaction we had on Yammer, a mobile app is a necessity...
Considering the how this forum works, I prefer it would be a responsive web design and in case anyone wanted to add it in their phone, they would just pin it.
I don't think there is a need to create an application for it.
Applications would required regular updates and there are other challenges and PWA would be better solution where we have access to the latest version and we could access the website without installing anything.
