Does your startup need a mobile app?
Perhaps. Perhaps not. It depends on what your product or service is, what your budget is, and what your audience is.
Product or service
This is an obvious way to rule out certain businesses. Dairyland doesn't really need a mobile app - if I want chocolate milk, I'll go to the store and buy some. But a magazine, for example, better have one: their readers, unless the publication is Amish Lifestyle, want to access your news on the fly. A retailer may not have any urgent need to develop an app, as shopping on a mobile device is a clumsy experience indeed, but certainly your super-unique group-buying startup must give instant access to consumers via smartphone, especially one of those new-fangled location-based ones.
It's moslty cut-and-dry, but there's always room for innovation. Use a mobile app to launch a campaign, or just test the waters to see how many of your consumers bite. This is one way to better understand your audience - which brings us to the next point.
If you provide a senior-friendly taxi service, for example, don't bother making a mobile app. A taxi service is a great business to utilize the mobile application realm, but not one that targets Granny Agatha who will mumble, "What's a smartphone?!" before thwacking you with her cane.
That doesn't mean mobile apps only appeal to geeks, of course, but your audience needs to meet certain critera: do a large number of them have or want mobile devices? Are they commuters or travellers or do they otherwise spend time away from the home computer and office? Does your product or service have extra perks being mobile, or does mobile improve its quality or effectiveness in some way that the consumer will recognize?
Money. Not the best thing to talk about so close to Christmas, I know. But if you bust your financial balls so your brand new mobile app can burst onto the scene, only to bust itself and become the bane which bankrupts your brand... that's bad. Know how much you can afford - if you truly need one at all - and don't go over budget.
Shop around and do your research; don't rush into anything. Launching a crappy app is a difficult wound to heal, especially if it damaged the wallet too. Remember: Unless you sneak in advertising or your app somehow commands high-downloads at a premium price, you won't tangibly realize a return on the app. It's about creating a positve user experience, boosting user engagement, and promoting - direct profits are never a chief goal.
Which platforms to use?
iPhone, BlackBerry, Android, Symbian, Bada, Windows mobile... and an increasingly wide of tablets to boot. It's certainly not cheap to make your app available on every platform - but it certainly isn't necessary either. While there is some overlap, key distinctions between demographics of these platforms do exist, so do your research.
For example, Android phones are male-dominated, while iPod Touch consumers are mostly teenagers, and iPhone users are more willing to pay for apps than most. BlackBerry uses tend to be more business-savvy professionals. Remember, however, one tricky point: Launching app for one or two platforms but no others may offend some or many of your consumers, especially if you targeted the wrong ones.