Here is a list of all files with brief descriptions:

_kiss_fft_guts.h
add_crc.h
add_crc_impl.h
api.h
crc_verif.h
crc_verif_impl.h
data_source.h
data_source_impl.h
deinterleaver.h
deinterleaver_impl.h
dewhitening.h
dewhitening_impl.h
fft_demod.h
fft_demod_impl.h
frame_sync.h
frame_sync_impl.h
gray_demap.h
gray_demap_impl.h
gray_mapping.h
gray_mapping_impl.h
hamming_dec.h
hamming_dec_impl.h
hamming_enc.h
hamming_enc_impl.h
header.h
header_decoder.h
header_decoder_impl.h
header_impl.h
interleaver.h
interleaver_impl.h
kiss_fft.h
modulate.h
modulate_impl.h
payload_id_inc.h
payload_id_inc_impl.h
RH_RF95_header.h
RH_RF95_header_impl.h
tables.h
utilities.h
whitening.h
whitening_impl.h