Mobile apps can certainly be profitable, especially if you
maintain in-app purchases and "freemium" business models,
and so it is worth your while to protect them from imitators and
copycats. Fortunately, apps can be patented in some
jurisdictions.
Suppose you have developed a trail-blazing mobile app or
feature. In that case, the question you ultimately need to answer
is whether it makes sense, from a commercial point of view, to
pursue patentability or whether other Intellectual Property (IP)
protection might suffice, namely copyrights, design rights or
trademarks.
If you determine that it does make sense, you must then figure
out how to patent your app. To this purpose, you should rely on the
counsel of a patent attorney and other experts to prevent the road
to patent registration from turning into a dead end.