This is admittedly a very niche product for a specialized group of (stock market) traders: For the past two years my bread and butter has been finding stocks that pop and sell CSPs (cash secured puts) against them, generally where they were before the pop. I found the best prices to sell frequently occur immediately after it pops. So, I slapped together a little script that beeps at me when stocks pop, drop, or are halted... then I take a look at them for further investigation. The simple logic of comparing where the prices were ~5 minutes ago to now was good enough for me, and so I did this for the last ~2 years. Now, I recently got motivated to slap a UI together and put it on an old domain I had and share it with my fellow internet chums.