Y. Charlie Hu, a professor at Purdue University, recently developed an app that can help prolong the battery life of smartphones, Business Standard reported.

Hu's creation, the Estar app, notifies users about other application that can easily drain the batteries of their devices.

Using a system, Estar shows how fast an app can drain a smartphone's battery. It then compares the app's energy needs to other in the same category.

"Upon starting, Estar offers two options," Hu explained. "The first is to search for energy-efficient apps in Google Play. In addition to the popularity rating available from Google Play, Estar displays a color-coded, five-star energy rating for each app that shows how fast an app will drain the phone battery."

"Users can then use this information to make decisions on which apps they choose to download, including energy-efficient apps, i.e., those having high energy ratings by Estar," the professor added.

Aside from rating an app's battery-usage, Estar also monitors the amount of energy it consumes. Users can then use this data to stop the app or remove it completely from their phones, according to JCOnline.

"The second option is to report on the energy drain of apps already downloaded and running on the user's phone, and in doing so, identify and warn the user which apps are draining an excessive amount of battery," he said.

"The user can then take actions such as stopping or removing the app to extend the battery life," Hu continued.

According to Hu, Estar, which can be downloaded for free in Google Play, works by searching through the online store's categories and uses data from scenario-based statistics to analyze an app's battery consumption, HNGN reported.

"Currently, Estar uses the Google Play categories to find apps that perform similar functions, for example 'Books' and 'News' are two categories of apps in Google Play," he said.

"Estar uses crowd-sourcing technology to find how fast an app drains battery on users' phones under actual usage scenarios," he added. "It collects app usage statistics on many smartphones and our backend server then derives the expected power drain for that app."