For the past 2.5 months, we've been offering our 'pro' upgrade at an early-adopter discount of $1.99, today we launched a new version with a few more pro features and bumped the price up to $4.99.
We've done little research to know what the optimal pricing is for the pro version, but with 2.5 months of data at $1.99, it's a good time to test the price bump.