app_description.txt

Zingo! A Zcash Application

Use zero knowledge cryptography to transact, and to manage your transaction history, in a private and mindful way.

Take exclusive and unique control of your financial history. Use this unique insight into your
own financial behavior, to introspect on how you spend money. Share insights on your terms. 
Establish healthy relationships with diverse economic communities.

Only you have the power to share your information! Your perspective matters. You matter.

When you send Zcash you can write a memo containing anything you like. When you receive
Zcash you also receive the memo that the Sender wrote. As with most cryptocurrencies, wallets
routinely send transactions to themselves to recover "change" from the transaction.  In this case, where
the application is both the Sender and the Receiver, Zingo uses the memo system to write
notes to itself about the transactions it builds for the User.

Zingo extracts that data to provide insights exclusively to you.  In our initial release we
already use this introspective mechanism to "remember" which full Unified Addresses you've previously sent Zcash.
In other words, Zingo keeps track of who you've sent Zcash to, on the blockchain. This "Address Book"
of people you've "Sent To" in the past is completely private and, as long as you properly protect your
seed-phrase, will be fully recovered even if you lose your device. 

We're currently implementing another use of these on-chain memos, that will allow you to keep track (even if 
you lose your device) of which addresses you previously produced to receive funds at. That is, you'll always
have a full list of all the addresses you asked people to use to send you zcash.

Taken together these two instrospective mechanisms provide you with insight into who you've sent
funds to, and who you've asked for funds from.  This is just the beginning!  We intend to implement
mechanisms to allow users to share their insights in an anonymous, and economically viable way that
will allow communities to aggregate around marketplaces of interesting insights!

Your on-chain transaction details are never exposed to any third party. By providing you with private insight into
your own economic behavior, we are enabling everyone to make healthier financial decisions.
We anticipate diverse communities that form around different kinds of insights, to collaborate
on shared values.

Technical Detail of UA Caching:

Zcash supports a multi-protocol Unified Address that enables the protocol to upgrade to newer versions
without breaking backwards compatibility with earlier versions. This Unified Address system is 
implemented by clients off-chain. Clients share Unified Addresses with each other, the Unified
Addresses contain Protocol Version Specific Addresses that the client can unpack, and publish to the
blockchain as part of the transaction that it builds. This means that the on-chain address associated
with a transaction does not contain all of the information the Sending-Client received as a "Unified Address"
from the Recipient-Client, off-chain.  If the Sending-Client simply recorded the UA off-chain then, in the
case of Re-Sprouting the Client from its SeedPhrase, there'd be no way to recover that relationship data.
Zingo solves this issue by recording the original recipient provided UA in the memo field of change from the
transaction.