Just how big is the mobile app market?The answer is $25 billion in 2013 according to ABI Research.That's just a drop in the bucket compared to what's coming in 2018 when ABI Research predicts mobile app revenue will climb to $98 billion.Not surprisingly, 65% of the predicted 2013 mobile app revenue will come from devices running the Apple iOS, 27% from Google's Android, and 8% from other mobile platforms.The Apple iOS is still the dominant player when it comes to mobile apps, and that's unlikely to change in the near future despite the fact that Google is currently the mobile platform market share leader.According to comScore, January 2013 mobile platform market share percentages were as follows:

1. Google = 52.3%
2. Apple = 37.8%
3. BlackBerry = 5.9%
4. Microsoft = 3.1%
5. Symbian = 0.5%

ABI Research also reported that the majority of the $25 billion in mobile app revenue predicted in 2013 will come from smartphones. This year, smartphones are expected to generate $16.4 billion in mobile app revenue, which is nearly double the $8.8 million in revenue expected for tablet apps.In 2013, far more people own smartphones than tablet devices, so this prediction isn't surprising. However, when you move further into the future, the prediction changes, and that's when things get interesting.According to ABI Research, the mobile app market will look very different in 2017 when revenues from tablet apps will catch up to revenues from smartphone apps. By 2018, ABI Research predicts that tablet app revenues will surpass smartphone app revenues.Aapo Markkanen, an ABI Research senior analyst, posits that the shift to tablet mobile apps will come from markets that are under-served today. He explains, "The really big deal about tablets is how they will help to finally bring the computing age to, for instance, children and the elderly."Bottom-line, if these predictions are true, the mobile app market will be a $1 billion per year powerhouse within five years and much of that growth will come as a result of increased tablet device ownership. Of course, five years is a long time in the mobile-tech world. Tablets could seem antiquated by 2018. We'll have to wait and see if these predictions come true or not. What do you think? Will tablets rule in 2018?Image: Yutaka Tsutano