The biggest concern while hiking is probably “How much further do I have to climb?” This app verbally notifies you of your current altitude at specified intervals. You can also set your target altitude and receive notifications for how many meters remain. You can customize the spoken text to your liking.

★Special Notes
・To reduce load on the Geographical Survey Institute server, notification intervals are set in minutes
・Voice notification invokes when you move more than 20 meters from the last notified location *and* the interval time has passed
・Altitude unit is in meters only
・altitude info by received GPS data has significant error, so the app uses the Geospatial Information Authority of Japan's API service for retrieving the current altitude; Internet connection is required while running the app.
・The voice configuration can be changed in Android Settings → Accessibility → Text-to-speech output