could someone tell me how to add a recipe in OpenGeo Suite please. I would like to submit a Tree sub-layer in a geoexplorer map.
There is no official recipe collection for GeoExplorer, but you could contribute your code as plugin to the Suite SDK by submitting a pull request for https://github.com/opengeo/gxp. If you feel that this is more suitable for documentation or a tutorial, then you could contribute to the SDK tutorial by sending a pull request for https://github.com/opengeo/suite/tree/master/docs/usermanual/source/apps/clientsdkintro.