At a high level glance this plugin appears to offer a free deals solution for WordPress. Just do not under estimate the amount of customization required to make it actually work.
Here are my findings.
1. The stock system is flawed when using vouchers. For example I created a deal, and initially started with 50 vouchers. The stock total (somehow) went down to -8. After this, I added more vouchers, but the stock level in the DB remained the same. To fix this expect to spend anything from a few hours to a day or 2, depending on your skill level.
2. The pricing system is flawed. For example, when entering a base price of 400, and not entering a deal price, the deal shows up as "free". When entering a base price of 400 and a deal price of 400, the item again is "free". This required an immediate fix.
3. Variations - there is a lot of code to suggest it is possible to create variations, however the documentation mentions nothing about this, searching Google didn't help either. Expect to spend no less than 1 painful day implementing a roll your own solution.
4. Paypal, initially it was working, but please do not ask me how. I spent hours just analyzing rather cryptic code, and eventually decided to fix it, so that Paypal redirection happens reliably. Expect no less than 1/2 a day debugging and pulling hair out if this happens to you.
5. Adding a custom currency. The instructions on the authors site really won't get you very far. I figured out how to do this myself, but it was a bit of a challenge.
Just generally I get the feeling that the author started with good intentions, but seems to have lost interest in the plugin. The code is cryptic making it hard to maintain.
The core concept is good, and it is does provide a nuts and bolts framework, but it is by no means a plug and play - ready for production plugin.