It is a nice little program, but fails on the second most important issue (the most important being calculating correctly): it's too slow to start. A calculator app needs to be instantaneous, which they more or less are on all platforms. The built in calc looks much uglier, but starts right away.

Is there anything that can be done, or is this based on some framework that will always take this long to load? Mine takes 5-6 seconds to start even on subsequent launches, which is a lot longer than 0 seconds.

Granted that the built in calc (or parts of it) might stay resident in memory all the time and have a huge benefit from that...