If you have a mobile-first business app, you're largely wasting your time if you're planning to acquire users via the app store or mobile advertising.
The reason is simple. There is almost no intent today on mobile app stores when it comes to business applications. And it's rare that mobile users pay much attention to business-centric mobile display ads.
Today, the most-successful mobile business app entrepreneurs are leveraging traditional SaaS lead-gen techniques. At the right point in the funnel (which varies by company), they direct prospects to download their app.
I'm optimistic that this will change at some point. As more mobile-first business apps emerge, I believe more business users will search for them via app stores. But, until then, stick to the desktop.
Note: If you're looking for a fantastic primer on inbound and oubound lead-gen, the best book on the topic is Predictable Revenue by early Salesforce employee Aaron Ross.