The Hema Explorer app is capable of displaying a compass indicator at top center of the map panel, which shows the general direction you are heading.
Not all devices have a compass sensor built in.
If your device does not have a compass sensor, the Compass setting may be greyed out completely under the Map Controls section of the Settings panel, as shown below. You cannot switch on the compass sensor if it does not exist on your device.
There is nothing you (or we) can do about this. Your device either has or does not have a compass sensor built in.
Not having a compass sensor will also mean that the course-up mode will not be functional on your device, as course-up mode depends on the device orientation, which is provided by the compass sensor.
If you want to check what sensors your device contains, you can install an app like CPU Z on your device. This will show you a whole lots of useful (and some not so useful) information regarding your device.
Link to CPU Z in the app store: