Being HAT–ready means your organisation embraces HAT ecosystem rules (http://hatcommunity.org/about-hcf/#governing), uses HAT Schema and APIs to allow HAT users to pull in their own data (stored at your buisness) into their HATs. In this case, your organisation should issue APIs to allow your customers to access their data. A data plug (a middle ware that connects your API to HAT) needs to be built to sync your customers' data to their HATs. You can either build and register your data plug here - https://marketsquare.hubofallthings.com/signup/shopper; or you can commission a data plug to be built, for example through HATDeX consultancy service [http://www.hatdex.org/hatdex-consultancy-services/].
Once your data plugs is certified and active in the HAT ecosystem, you can create a customised view on RUMPEL to integrate your organisation's data with other types of HAT data, and allow all HAT users to see them. To get started, please join of developers' forum at http://forum.hatcommunity.org/, and you can get the RUMPEL open source code here - https://github.com/Hub-of-all-Things/rumpel .