Introduction
Quack is a 3rd service plugin based on Nxt Phased feature for directly exchanging
Asset<>Asset, Asset<>Currency, or Currency<>Currency without need to convert to NXT.
Quack enables easy, safe and secure atomic swaps of Nxt-based Assets and Currencies.
The creator,
blackyblack1,is a trusty activist around Nxt community.
Following Tutorial mainly includes Download,Install,and Use it.
Download
or
InstallMove unzipped
quack folder to [NRS directory]/nxt/html/ui/plugins:
Use1. Enable Plugin.
Plugins are disabled default,need to enable it by setting gear on top right corner of wallet.

2. Restart Client.
Restart client and click Plugins button on left side,you will see Quack is running.

3.Use it.
Whole Process as following:
Sender Create Sell Swap Order ->Receiver Accept ->Sender Accept ->Swap Done
- Sender Create Sell Swap Order
Click Quack plugin, then
Create Swap button:

Fill Receive Account,Select Asset type(Asset/Currency/NXT),and Quantity;
Fill desired assets to Receive and Quantity;
Type passphrase and click "Create" to initiate your Sell Swap Order.
Example:Receipt Account:NXT-9ZM9-U9ZF-2LZ8-G46WK
Asset Type: Asset
Asset id: Quantity
2069092550347872704 (Bitfirm) 3
1584198250936051677 (CoreMedia) 1
Receive
Asset Type:Asset
Asset id: Quantity
18128686802152832026 (Nxttycoin) 8

Sell Swap Order is created with status
pending, wait for receiver accept.

- Receiver Accept Swap Order
Receiver click Quack plugin:

Click
Accept status button ,type passphrase and click Accept:

Swap Order status changed to
pending:

Now sender need to accept Swap Order with status
Accept:

Sender Click
Accept stutus button ,type passphrase and click Accept:

Swap Order is done successfully:

Click
Done button to see Quack details:
As you see,both sides have confirmed swap order,and the status is marked by ok.

Sender and Receiver will receive assets immediately when swap order was done.
3 NXT with each asset for swap and 3.5 NXT(2.5NXT tips+1NXT transaction fee) from sender tipped to Develper's account each swap order;
Developer recommends to wait for at least 3 confirmations to accept the order for safe exchange.