This is Oppo Theme Creator  V 3.0.2.0 Portable for 400x800 Android Device.

Normally you can download original version From oppo website here to check if your device supported. My device is Oppo R821 Find Muse and that is not on the list, but i see with zip software it has same structure from .theme file i have. Is theme.apk and assets folder insize archived .theme files, so my devices supported by this apps. Your phone my have not on the list, but if you have 480x800 device like Find Piano, maybe you can use this too.

If you install this software where you download it from oppo website it say error when chosing model phone, say Runtime Error Terminate unusual way. Even i can solve that issue, i found another problem that is cannot save my theme, the error say Failed to open... blah i want to save not to open... bzzz crazy error. Later i know this due to misstype on my windows who can operate chinese character typeset.

So this is modification of my work to fully Run Smoothly on my windows 7 english version.

You can click download link at the bottom of this post.

How to:

- Extract Downloaded Zip

- Run ThemeTopFrame.exe

- Make Your Theme

- Save to get .theme files

* Copy that themes on your Phone SDCARD to /Themes

* Open your Stock Launcher.

* Choose Theme tab & your modified theme.

Below is Screenshoot of that Software if image is looking small, you can clik to erlange.

GUI is in Chinese, but with interactive image you can understand with no time.

---Update 2

I have made translation ot that Theme Maker, but its not 100% let say it just 95% text has been translated.

Just download zip in link at the bottom and extract to your old Theme Maker.