It’s selling about a dozen a day or so, which I feel is pretty good for such a niche app. The sales were about double that for the first week or so when it was just 99 cents but it always drops after the initial sales.
I think going with $0.99 for the first week and then settling in to $1.99 was the right strategy. My impression is that the difference between two such low prices isn’t enough to significantly affect someone’s decision to buy an app. Either they want it or they don’t.