This apps creates zip themes for webOS. Such themes can be uploaded to both the PreCentral Theme Gallery and PreThemer.

What's more, with v3.0, it fully support the json zip format used by the Theme Manager on-device app for next-gen webOS theming.

Official Discussion Thread: http://forums.precentral.net/canuck-coding/203952-webos-theme-builder-v3-0-a.html