If you currently have another version of the BitMEX app installed on your Android device, you will need to uninstall it before installing the APK.
Enable installing ‘unknown apps’ on Android
Go to Settings
Tap Security
Tap Device Administration
Enable Unknown Sources
Note: The location of this setting can vary across devices and versions. If you can’t find this setting under the location above, try searching for ‘Enable Unknown Sources’ in settings.