[Galaxy S 4 i9505 Android Development] :
# WIFI

/system/bin

dhcpcp

ip

iptables

wpacli

wpa_supplicant

ip

ip6tables

iptables

iv6tether

insmod

ping

pnpmgr

pppd

racoon ???

udhcpd ???

wpscl_test_cmd ???

/system/etc/

dhcpcp (folder)

firmware

android.hardware.wifi.direct (in permission folder)

android.hardware.wifi (in permission folder)

wifi (folder)

wifoffloadpkg

/system/lib/

libhardware_legacy.so <---! This is most likely not needed to touch if you change this phone will not boot

libhdcp2.so

libwpa_client.so

modules (folder)

# Sound

system/bin/

asound ???

mediaserver <- sound should need correct mediaserver to work

sound

/system/etc

audio/effects.xml

audio_policy.xml

AudioBTID.csv <hink this is HTC relevant

AudioBTIDnew.csv < think this is HTC relevant

media_codecs.xml

media_profiles.xml

com.google.android.media.effects.xml (permission folder)

/system/lib/

alsa.msm8960.so (HW folder)

audio_policy.default.so (HW folder)

audio.usb.default.so (HW folder)

libalsa-intf.so

libaudio-resampler.so

libaudioeffect_jni.so

libaudioflinger.so

libAudioTrimmer.so

libaudioutils.so

libmedia_jni.so

livmedia_native.so

libmedia.so

libmediaplayerservice.so

libmm-audio-resampler.so

libMusicVisualizer.so (for visualising effects i guess)

libSR-AudioIn.so

libwebrtc_audio_preprocessing.so

SoundFX (folder)

# GSM/DATA/NETWORK

/system/bin/

netcfg

netd

netmgrd

netsharing

netstat

rild

sec-ril

/system/camerdata/

every file in it

/system/etc

apns_conf.xml

android.hardware.telephony.gsm.xml (permission folder)

/system/lib/

libreference.ril

libril-qc-qmi-1.so

libril-qcril-hook-oem.so

libril.so

libsecril-client.so

# Camera

/system/bin/

awb_camera

flash_camera

mm-jpeg-dec-test

mm-jpeg-dec-test-client

mm-jpeg-enc-test

mm-jpeg-enc-test-client

mm-jps-enc-test

mm-mpo-dec-test

mm-pp-daemon

mm-qcamera-app

mm-qcamera-daemon

mm-qcamera-test

mm-qcamera-testsuite-client

mm-vdec-omx-test

mm-venc-omx-test720p

mm-video-driver-test

mm-video-encdrv-test

v4l2-qcamera-app

/system/etc/

android.hardware.camera.flash-autofocus.xml (Permission folder)

android.hardware.camera.front.xml (Permission folder)

/system/lib/

camera.msm8960 (HW folder)

libcam_oem_plugin.so

libcamera_client.so

libcamera_metadata.so

libcameraasd.so

libcameraface.so

libcameraapp.so

libcameraservice.so

libchromatix_ar0260_default_video.so

libchromatix_ar0260_hdr.so

libchromatix_ar0260_preview.so

libchromatix_ar0260_zsl.so

libchromatix_imx074_default_video.so

libchromatix_imx074_preview.so

libchromatix_imx074_video_hd.so

libchromatix_imx074_zsl.so

libchromatix_imx091_default_video.so

libchromatix_imx091_preview.so

libchromatix_imx091_video_hd.so

libchromatix_imx135_default_video.so

libchromatix_imx135_hdr.so

libchromatix_imx135_hfr.so

libchromatix_imx135_preview.so

libchromatix_imx135_zsl.so

libchromatix_imx175_default_video.so

libchromatix_imx175_hdr.so

libchromatix_imx175_hfr.so

libchromatix_imx175_preview.so

libchromatix_imx175_zsl.so

libchromatix_mt9e013_default_video.so

libchromatix_mt9e013_preview.so

libchromatix_mt9e013_video_hfr.so

libchromatix_ov2720_default_video.so

libchromatix_ov2720_hfr.so

libchromatix_ov2720_preview.so

libchromatix_ov2720_zsl.so

libchromatix_ov2722_default_video.so

libchromatix_ov2722_hdr.so

libchromatix_ov2722_preview.so

libchromatix_ov2722_zsl.so

libchromatix_ov4688_default_video.so

libchromatix_ov4688_hdr.so

libchromatix_ov4688_hfr_60fps.so

libchromatix_ov4688_hfr.so

libchromatix_ov4688_night.so

libchromatix_ov4688_preview.so

libchromatix_ov4688_video_hdr.so

libchromatix_ov4688_zoe.so

libchromatix_ov4688_zsl.so

libchromatix_ov5647_default_video.so

libchromatix_ov5647_preview.so

libchromatix_ov5693_default_video.so

libchromatix_ov5693_hdr.so

libchromatix_ov5693_hfr.so

libchromatix_ov5693_preview.so

libchromatix_ov5693_zsl.so

libchromatix_ov8825_default_video.so

libchromatix_ov8825_preview.so

libchromatix_ov8838_default_video.so

libchromatix_ov8838_hdr.so

libchromatix_ov8838_hfr.so

libchromatix_ov8838_preview.so

libchromatix_ov8838_zsl.so

libchromatix_ov9726_default_video.so

libchromatix_ov9726_preview.so

libchromatix_s5k3h2yx_default_video.so

libchromatix_s5k3h2yx_hdr.so

libchromatix_s5k3h2yx_hfr.so

libchromatix_s5k3h2yx_preview.so

libchromatix_s5k3h2yx_zsl.so

libchromatix_s5k3l1yx_default_video.so

libchromatix_s5k3l1yx_hfr_60fps.so

libchromatix_s5k3l1yx_hfr_90fps.so

libchromatix_s5k3l1yx_hfr_120fps.so

libchromatix_s5k3l1yx_preview.so

libchromatix_s5k3l1yx_video_hd.so

libchromatix_s5k3l1yx_zsl.so

libchromatix_s5k4e1_default_video.so

libchromatix_s5k4e1_preview.so

libchromatix_s5k6a1gx_default_video.so

libchromatix_s5k6a1gx_hdr.so

libchromatix_s5k6a1gx_hfr.so

libchromatix_s5k6a1gx_preview.so

libchromatix_s5k6a1gx_zsl.so

libchromatix_s5k6a2ya_default_video.so

libchromatix_s5k6a2ya_hdr.so

libchromatix_s5k6a2ya_hfr.so

libchromatix_s5k6a2ya_preview.so

libchromatix_s5k6a2ya_zsl.so

libchromatix_s5k6b2yx_pip.so

libchromatix_s5k6b2yx_preview.so

libchromatix_s5k6b2yx_smartstay.so <- not needed

libchromatix_s5k6b2yx_video.so

libchromatix_s5k6b2yx_vt_hd.so

libchromatix_s5k6b2yx_vt.so

libchromatix_vd6869_default_video.so

libchromatix_vd6869_hdr.so

libchromatix_vd6869_hfr_60fps.so

libchromatix_vd6869_hfr.so

libchromatix_vd6869_night.so

libchromatix_vd6869_preview.so

libchromatix_vd6869_video_hdr.so

libchromatix_vd6869_zoe.so

libchromatix_vd6869_zsl.so

libhtccamera_yushaniiproc.so

libhtccamera.so

libimage-jpeg-dec-omx-comp.so

libimage-jpeg-enc-omx-comp.so

libimage-omx-common.so

libImageAlignment.so

libmmcamera_aec.so

libmmcamera_faceproc.so

libmmcamera_frameproc.so

libmmcamera_hdr_lib.so

libmmcamera_image_stab.so

libmmcamera_imx091.so

libmmcamera_interface.so

libmmcamera_interface2.so

libmmcamera_plugin.so

libmmcamera_rawchipproc.so

libmmcamera_rubik.so

libmmcamera_statsproc31.so

libmmcamera_wavelet_lib.so

libmmjpeg_interface.so

libmmjpeg.so

libnativedocviewer.so

liboemcamera.so

libpixelflinger.so

libvideo_cor.so

#Decoder

/system/lib/

libstagefright_soft_g711dec.so

libstagefright_soft_h264dec.so

libstagefright_soft_h264enc.so

libstagefright_soft_mpeg4dec.so

libstagefright_soft_mpeg4enc.so

libstagefright_soft_rawdec.so

libstagefright_soft_vorbisdec.so

libstagefright_soft_vpxdec.so

libstagefright_wfd.so

libstagefright_yuv.so

# Bluetooth

/system/bin/

bluetoothd

bma150_usr ???

bmgr ???

/system/etc/

bluetooth folder

android.hardware.bluetooth.xml (permission folder)

/system/lib/

libandroid.so ???

libbluedroid.so

libbluetooth.so

libbluetoothd.so

Again theres probably more files related to audio, bluetooth and camera, wifi i don't remember all of them