Carat 2.01 can also show App Recommendations on iOS 9.0 through 9.3.2!

Our next release will include settings recommendations for iOS 9.3.3+. We are already collecting the data for this, so stay tuned!


Carat is the first app to generate personalized recommendations for improving your battery life. After observing your use of the device for *a week or more*, it will start to generate reports just for you. You should open the app once every day or so, with an Internet connection turned on, until you start seeing results.

Although Carat uses Location Services (thus displaying the little icon), it is NOT using your GPS and is NOT running in the background. The app uses almost no power.

** Thank you! **

Ever wondered why your battery is draining so quickly? Just install Carat, open it every few days with an Internet connection turned on so it can send data to our servers, and within a week Carat will start recommending Actions (just for you!) and even predicting the improvements you will see. Although Carat cannot measure energy use directly, it infers what apps are responsible using advanced machine learning methods.

And it's free!

As you use your device, Carat occasionally takes measurements and sends them to our backend servers in the cloud, where we apply cutting-edge algorithms to determine what steps you can take to use less energy. By collecting snippets of non-personal data from a large number of devices, Carat does not need to run continuously in the background. Nothing we collect identifies you, personally.

Carat will tell you which apps generally use a lot of energy and and those that specifically do so on your device (but not on most others). This does not make an app 'bad', but this advice can help a user improve their battery life.

== Carat Features ==

- Action List telling you how to improve your battery life and by how much
- Device information detailing exactly what data we are recording
- Reports apps that are using lots of energy and whether that is happening on other devices, too
- Detail views let you dive down into the data
- Low-overhead sampling requires almost no energy or CPU
- J-Score tells you how your battery efficiency compares to other users
- Sharing features let you post/tweet/blog about your experience; more users means more data which means better recommendations for you

Carat is under active development by a team of researchers in University of Helsinki. We are constantly making improvements, adding features, and giving you more knowledge about how your device is using energy. Remember, knowledge is power!

What’s New

Version 2.014

New icon
Fix display of model name for newer iPhones. Get model names from server-side.

Ratings and Reviews

3.7 out of 5
12 Ratings

12 Ratings

Skadood1 ,

Works but I question the accuracy

Works after a number of days or weeks of waiting, but my graphs don't show much data, and the data doesn't change much when I drastically change behavior. J-score seems to work well for me.

I've heard that the researcher/developer only is able to work on this part time and that he has problems trying to get it to scale to hundreds of thousands of devices spewing data into him. Give them a break, it's research, and probably not well funded. A private company would have been pulling in money and been able to hire a person knowledgable at scaling this. This - its free, no money being made.

Smoker Dokers ,

Only Works w iOS 9.3.3 or older.

As stated above, so if you have an iPhone 5 or newer this app will not work. After opening religiously 10 times a day or more for 8 days, over 600 data points, to my dismay I noticed the disclaimer hidden I am mentioning to you when trying to find individual apps that were draining battery. Bummer. 6 years ago it was probably a really cool app. It was able to tell me my J score however, which was 25, so 75% or the participants have a better battery than me. Depressing. The whole thing was rather depressing. My fault. Disclaimer was always there.....

9robins ,

iPhone Fountain of Youth

I mentioned this app to a colleague who thought he would need to buy a new phone because his current phone was slowing down. I got a message later that he had made the adjustments suggested by the app and it "was like having a brand new phone."

App Privacy

The developer, University of Helsinki, has not provided details about its privacy practices and handling of data to Apple.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


University of Helsinki
14.3 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, Finnish

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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