# Karoo Powerbar Extension > [!WARNING] > Only tested on Karoo 3 Simple karoo extension that shows an overlay progress bar at the bottom of the screen. For Karoo 2 and Karoo 3 devices running Karoo OS version 1.524.2003 and later. ![Powerbar](powerbar0.png) ![Settings](powerbar1.png) ## Usage Install the app and start it from the main menu. You will be asked to grant it permission to show it on top of other apps (i. e. the karoo ride app). You can select one of the following data sources: - Heart rate - Power - Average power over the last 3 seconds - Average power over the last 10 seconds Subsequently, the power bar will be shown at the bottom of the screen. The bar will be filled according to your current power output / heart rate and will change color depending on the intensity, as setup in your power / heart rate zones. ## Installation Currently, Hammerhead has not yet released an on-device app store that allows users to easily install extensions like this. Until it is available, you can sideload the app. 1. Download the apk from the [releases page](https://github.com/timklge/karoo-powerbar/releases) (or build it from source) 2. Set up your Karoo for sideloading. DC Rainmaker has a great [step-by-step guide](https://www.dcrainmaker.com/2021/02/how-to-sideload-android-apps-on-your-hammerhead-karoo-1-karoo-2.html). 3. Install the app by running `adb install app-release.apk`. ## Credits - Icons by [boxicons.com](https://boxicons.com) (MIT-licensed). ## Links [karoo-ext source](https://github.com/hammerheadnav/karoo-ext)