Using it at work as team communication tool, on mobile am using the web client which is not that good...

However we are trying to get away from Slack... since we have hit the limit of the free version where history diappears about the same rate new messages come in (which is fairly quick)
Licencing the paid version is a no-no since we have about 350 users... the fees quickly climb up to amazing annual sum.
There's also the fact that when you are using Slack you trust your company confidental information to a cloud service hosted by a 3rd party... not nice IMHO.

However the free/self-hosted alternatives all have some shortcomings, and the inertia of hundreds of people using a system is large --> it is fairly difficult to migrate...

TL;DR having a native Slack client would be nice but I am not prepared to pay for it more than maybe 20 euros or so.