Tasa Graphic Arts, Inc. today announces two new iOS apps for geology students. The geotimescale Enhanced app is now available for iPhone and the iPod touch and the geotimescale Enhanced HD app is available for iPad. These apps illustrate significant events and periods of time in Earth’s history. The Geologic Time Scale shows the names of the eons, eras, periods, epochs, and ages along with their corresponding dates. Each app also includes illustrations and information for significant events.