ChromiumOS default calculator app, fixed!
Just the default ChromiumOS Calculator, (https://chrome.google.com/webstore/detail/calculator/joodangkbfjnajiiifokapkpmhfnpleo) but with the ugly green logo reverted back to the (many years standing), original Chromium blue-ish logo. Also the manifest has been updated and copy/paste loading & unloading fixed!
Ugly logo for comparison:
Simply download Calc.crx, open chrome://extensions, enable developer mode (there is a toggle in the upper right hand corner of the page), then drag and drop the .crx into the page. It will prompt for installation just like any other Chrome Web Store App.
2.2.9 (First release) -- Manifest fixed and logo replaced with original (good & proper!) one.
2.3.0 (Second release) -- Manifest updated and locales updated.