In my opinion, too much emphasis is put on free vs paid and monetisation strategies. Very few people make money directly from apps and the ones that do are probably games.
The people making the real money are those that are supplying apps for free and instead selling or promoting something else. Almost every industry has opportunities to use apps as enablers of core business. For example, in my case, in the last year I have worked with companies using apps in healthcare, insurance, retail and hospitality. The retail solution was created so that it was white label to allow use by my client’s many clients. None of the apps I created over the last year for clients was sold, ad-funded or freemium funded. Instead, the apps support existing businesses to sell more of their core product or service.
I believe there are many opportunities such as these that go beyond the free vs paid mentality. Furthermore, if they are implemented in such a way as to be re-brandable via white labelling then this leverages the opportunity to make it even larger.