GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.

XE.com - XE.com Inc. (XE) is a Canadian online foreign exchange services company.

LabPlot - LabPlot is a KDE-application for interactive graphing and analysis of scientific data.

Tweetbot - Sync your timeline across your iPhone, iPad, and Mac. Mute tweets by user, hashtag, tweet source, or keywords (including regex). 3rd Party support for image, video, read later, and timeline sync services.

Matplotlib - matplotlib is a python 2D plotting library which produces publication quality figures in a variety...

Valuta+ - Valuta+ is a super simple & free currency converter. The interface is fast and makes you convert exchange rates very easily. This app have more than 160+ currencies for you and is always updated.