[Tizen Software Development] adfree:
It is possible to create own Theme.tpk, with Paint... and Text Editor...

If you have valid Theme as Template... for my SM-Z130H.

I have created 250 KB template...

It is possible to replace Picture in SPI Format... file extension *.spi with PNG. :D

:angel:

I have replaced Wallpaper and Screen lock Wallpaper...

Edited in themes.json... changed file extension to PNG

Replaced few Icons with PNG as test...

I will do some more changes and tests...

Then I could upload Screenshots... or maybe little Video... and/or... my Theme.tpk ...

Later more... :cowboy:

Best Regards

Edit 1.

Little bit background info...

This is what we can find inside Theme.tpk, if we would have one. :D

example for Theme	Screen Resolution	SM-Z300H	SM-Z130H
720 x 1280 Pixel	480 x 800 Pixel

tizen-manifest.xml

-----------------------------------------------------------------------------
shared\res\themes.json------------------------	simple text file
-----------------------------------------------------------------------------
shared\res\home\1709552274811.spi-------------	replace with PNG
-----------------------------------------------------------------------------
shared\res\home\Home_screen_0198_home_screen_app_icons_icon_tray5011.spi	???	???
-----------------------------------------------------------------------------
shared\res\home\appicon\8-4-1-10_home_screen_app_icons_clock5011.spi	???	???
shared\res\home\appicon\8-4-1-11_home_screen_app_icons_settings5011.spi	118 x 118 ???	81 x 81 ???
shared\res\home\appicon\8-4-1-13_home_screen_app_icons_memo5011.spi
shared\res\home\appicon\8-4-1-14_home_screen_app_icons_my_files5011.spi
shared\res\home\appicon\8-4-1-16_home_screen_app_icons_video5011.spi
shared\res\home\appicon\8-4-1-17_home_screen_app_icons_calculator5011.spi
shared\res\home\appicon\8-4-1-18_home_screen_app_icons_smart_mananger5011.spi
shared\res\home\appicon\8-4-1-1_home_screen_app_icons_phone5011.spi
shared\res\home\appicon\8-4-1-2_home_screen_app_icons_contacts5011.spi
shared\res\home\appicon\8-4-1-31_home_screen_app_icons_voice_recorder5011.spi
shared\res\home\appicon\8-4-1-3_home_screen_app_icons_messages5011.spi
shared\res\home\appicon\8-4-1-4_home_screen_app_icons_internet5011.spi
shared\res\home\appicon\8-4-1-5_home_screen_app_icons_email5011.spi
shared\res\home\appicon\8-4-1-6_home_screen_app_icons_camera5011.spi
shared\res\home\appicon\8-4-1-7_home_screen_app_icons_galery5011.spi
shared\res\home\appicon\8-4-1-8_home_screen_app_icons_music5011.spi
shared\res\home\appicon\8-4-1-9_home_screen_app_icons_s_planner5011.spi
-----------------------------------------------------
shared\res\keyboard\2-2-1_common_button_bg_2501.#.png	41 x 50
shared\res\keyboard\2-2-2_common_button_bg_1501.#.png	41 x 50
shared\res\keyboard\2-2-3_common_button_bg_1501.#.png	41 x 50
shared\res\keyboard\2-2-4_common_button_bg_1501.#.png	41 x 50
shared\res\keyboard\2-2-5_common_button_bg_2501.#.png	41 x 50
-----------------------------------------------------
shared\res\lock\1709551834811.spi-------------	replace with PNG
-----------------------------------------------------
shared\res\preview\theme_homescreen.jpg	720 x 1280
shared\res\preview\theme_icons.jpg	720 x 1280
shared\res\preview\theme_keyboard.jpg	720 x 1280
shared\res\preview\theme_lockscreen.jpg	720 x 1280
shared\res\preview\thumbnail.jpg	188 x 334