Android: Java, C or C++?

Question

I wrote some simple apps in Android using Java.
But later I found this:

It provides headers and libraries that allow you to build activities, hand

Answer 1

Re-writing one of those "self-contained, CPU-intensive operations that don't allocate much memory" in C may improve the performance/battery life by a factor of 17 according to this investigation. This article finds that running CCTOOLS Fortran is even quicker. So alternative languages are well worth considering.