For 99% of the applications out there, there's no reason not to do it in the browser if you're starting from scratch today. Most (useful) mobile apps simply display remote content in a way that's contextually relevant to the moment (Yelp, shopping (ordering and product reviews), *Maps, news sites, social media, etc). There's no reason for any of those to be app based. Most apps that aggregate content are poorly designed and not updated frequently. Couple that with the fact that most do not have useful offline modes (the only reason to have an app for content, IMHO), it just makes sense to optimize for the mobile browser rather than spend all the time and effort on an app. Hell, even most games I play casually have no reason being written as apps any more - any word game or puzzler would work fine in the browser.
For context, I develop complex scientific software. We use the browser (desktop) as our client and push the limits of what you can do there. Mobile is not far behind and should be the first choice for new development.