Ken is happy to travel to your home if you are unable to travel to him.
A JP can witness your signature on a document.
A JP can certify copies of documents for you including cellphone texts and computer displayed results.
A JP can complete an affidavit for you. This is a document that is sworn on oath or affirmed and is normally used in a legal proceeding.
A JP can complete a declaration for you. This may be a statutory declaration made under the Oaths and Declarations Act 1957 or some other statute which provides for this to be done.