A free app for Android, by SpeedyMarks.
Altitude Free is an easy-to-use tool that will help you measure the altitude of your current position. You can choose between using the device’s built-in sensor or the satellite-based Digital Elevation Model (DEM). The accuracy of the measurement depends on the quality of the receiver on your device. If your device does not have a built-in sensor, the accuracy will be limited to the accuracy of the GPS sensor on your device.
The Altitude Free app is ideal for use on outdoor activities such as hiking, biking, or travel. It is useful for most people who want to measure their altitude at different points.
The app is simple to use and has a user-friendly interface.