I wrote twoCalc because I wanted a calculator with the features that I put into twoCalc:
  • a two-line editable display
  • the ability to enter formulas that would be properly interpreted with the correct operator precedence
  • a "tape" that records my activity
  • multiple memories
  • rounding to a specific decimal place
  • hex-binary-decimal conversions
  • simple unit conversions


Then, because I thought it would make people happy, I added in the ability to change the colors of the buttons and the calculator case. That may have been a mistake: people still complain about the colors and the extra CSS and HTML elements seem to cause it to sometimes have a delayed response to user input. This is most notable when running something else (such as a streaming music player) in the background. I've noticed similar lagginess in other apps, including some other calculators, but it seems to affect twoCalc more, possibly because of the extra CSS/HTML.

Fortunately, in almost all cases, while the feedback may be delayed, if you tap several numbers, even if there is a lag, it will generally catch up and handle all the key taps, probably when the CPU gets a moment to catch up to it.

Because I use twoCalc quite frequently myself, solving the lagginess problem is something I work on with every release--cutting out path length and trying various tricks to avoid garbage collection pauses and so forth. But it now looks like probably a restructure and simplification of the CSS and HTML is going to be what it takes.

Interestingly, I've seen very few complaints about a problem that I myself seem to see frequently, so maybe I'm being overly picky. Or maybe my Pre (a day one Sprint Pre) is a bit dodgy. So here's a poll for our twoCalc users.