While iphones are super popular these days with a lot of app developers, you cannot forget about Androids. Together, having comprehensive iOS/Android development is a great way to ensure your application is going to be successful. Aside from having the right amount of iOS/Android development, you need to ensure that your applications from top to bottom are properly set-up. Otherwise, there can be a lot of issues that will only exacerbate the issues that plague a lot of development houses. Way too often, people assume that just having the right amount of development alone will make just about any application have success.
While iOS/Android development is very important, you should also ensure you're doing a lot of quality assurance from both ends. This will ensure that the platform not only operates efficiently, but you'll want to verify whether or not your target demographic is actually a lucrative area of investment. Too often, people will fund an application and assume that just because it is somewhat unique that it's going to magically generate profit.
This couldn't be further from the truth. You need to recognize that it takes unilateral development expertise to make any application work, no matter how incredible it seems on paper.
Overall, while it is very successful and effective, there are way more efficient ways to make an application work in totality. Keep that in mind, and you'll be able to have success from just a marketing perspective alone, and also, aside from iOS/Android development.
However, no matter how unique your product is, you need to understand that unless it's proprietary, nothing is going to work properly. There are a whole lot of products in the market that work hard without being proprietary, but those are the exceptions. For your product. ensure that you're playing it smart rather than hoping for a miracle to come out of nowhere.