src - folder with test application
.ci/ndk_fortran.py - that script download android-gfortran archives from mzakharo repository,
download ndk-r21e, extract all folders and copy with replace arm-linux-androideabi-4.9 and aarch64-linux-android-4.9 content in the folders to android-ndk-r21e/toolchains
.github/workflows/android.yml - uses ArtemSBulgakov buildozer-action