1. What are DeMark Indicators?
2. What are VWAP (Volume-Weighted Average Price)?

I'm working with a client to develop a C# software application and need to implement the above features.

Not even 1 on AF?

I don't know what DeMark Indicators are.
VWAP is determined by taking all of the trades, weighted by their volumes, and then coming up with an average price.

For instance:
9:30 the stock trades $5, 1000 shares
10:30 the stock trades $5.50, 2000 shares
11:30 the stock trades $5.25, 3000 shares

VWAP = (5(1000) + 5.50(2000) + 5.25(3000)) / 6000 = 31750 / 6000 = $5.2916

Typically it's computed daily.

More info: http://en.wikipedia.org/wiki/VWAP

technical indicator to get a grasp of market manipulation eh?

i don't think it will work
1. there are "dark pools" that hedge funds and large institutions can trade in. their trades are not available for the public to see
2. it is easy to trade back and fourth between the same entity, creating the illusion of volume

For DeMark indicators, look here: http://www.tomdemark.com/

Hope it helps a little.