Sometimes clients hesitate over the cost and hassle of cross platform app development, with reason - we have at least 3 critical smartphone platforms in India - iOS, Android and BB - as well as Symbian and bada which form a chunk of feature phones. Add to this different form factors like tablet and smartphone and the many different flavors of Android. There is definitely a cost to this development.
In this context, this interview with Steve Allison, Senior VP of Telltale Games (creator of the popular Walking Dead franchise) makes for interesting reading.
Telltale Games had chosen to launch Walking Dead back in April on 4 platforms - PC, Mac, XBox 360 and iOS. Since the game is episodic, each subsequent installment also needs to be submitted, reviewed and released to each platform over a period of five to six months.
Allison notes that "Discovery and promotion on all these platforms is challenging, each in different ways, and trying to tackle them all at once is a chore. So publicity and marketing that is strong and reaches people in a platform-agnostic way is super-critical in order to put the game in a position to be sought after by all consumers regardless of platform. A combination of very strong prelaunch awareness and digital retailer platform relationships is the way to maximize consumer desire and secure the best discovery option each platform partner can offer."
Your cross platform app on mobiles may involve a lesser level of complexity than Telltale Games'. However, you probably need to have and maintain an app across platforms, simply to reach a diverse TG better. To not be present as an app on a particular platform, is to run the risk of losing that audience segment. Can you afford that? Probably not.