To create a lite account, you would create your own key and "register" it in the blockchain with an associated "human-readable" name. Any existing hive account including "app" accounts will be able to register such lite accounts with custom_json operations. Then 2nd layer apps can "recognize" the registered lite account and can "co-sign" transactions for it on the hive blockchain.
We'll provide a HAF app that supports the API for tracking lite account registrations and probably some other services as well.
It's very interesting, I can't wait to see it.