[dmitrygr]

5. how can I make $$$ from spending a few months writing a native client? Slack can cut me off anytime they get annoyed with me. So even if my client is better, they can decide i am a threat and cut me off.

Never build your future on someone else's platform.

[danShumway]

I completely agree, but this would fall under point 1 for me.

See Twitter for a good example of where business interests and API stability intersect in negative ways. I would make the point that if you don't trust a business to keep their official API stable, you probably shouldn't be building a community around their tools in the first place, regardless of whether or not they have a native app.