When the HP Touchpad was still new and webOS wasn’t completely dead yet, Conny and I created a series of calculator apps for webOS. The Touchpad came without a preloaded calculator app, so we gave a basic calculator away for free with in-app upgrade options for our more specialized creations. The whole thing ran under the name Calculator++ and taught me a lot about floating point errors. A lot.

Over time we put together a scientific

… and a personal finance calculator app.

We like to think that somebody probably found these a useful educational tool, but in the end the biggest educational effect might have been on us by teaching us about the quirks of Javascript and the webOS framework.