simple Wix addon development

Hello, We need a simple module developed for Wix - to be generic and uploaded to marketplace. the extension will do the following: 1) plugin name - Accessiblizer 2) add a settings page for the plugin - see attachment for example done on WP 3) by default a script <script /> will be injected before the </body tag. (script will be provided to winning freelancer) 4) injection will be both to management panel and visitor side. 5) on settings page (see attachment) 2 checkbox default checked - a) first checkbox if not checked will not inject anything, and disable the rest of the form (except save button) b) second checkbox will decide if to inject on management panel also or only on visitor side. 6) textarea on settings page - if any code there - inject code in it (will be entered within <script/> wrapper), if not - inject the default script. that's it !! took 3 hours on WP. NOTE: * code must be owned by us. * developed for English only - but use language files (not hardcoded) allowing future adding for more languages. * add all required files to zip - so we will be able to upload easily to marketplace. * must show it working on YOUR TEST SITE - so we will test it. * must be generic and work on all Wix versions - if any exceptions - please let us know on quote. * will be installed on many websites - and should be working seamlessly. thanks