For entertainment services such as Netflix and Spotify, the all-you-can-eat model has been tremendously beneficial -- both have racked up millions and millions of subscribers to date. When it comes to offering mobile applications, though, that idea of subscriptions hasn't really taken off. Regardless of whether you're an independent developer or a major brand, you depend heavily on storefronts like Apple's App Store or Google Play to sell and promote your content. But Opera Software, known mostly for its web browsers, wants to change this. With its new Subscription Mobile Store initiative, Opera wants to give companies a platform to offer their apps through, as the name suggests, a subscription service.