Hi Arturo;
The PowerServer "debugger" feature only works with Web Apps. However, here is what I do for Mobile application debugging ...
1) Publish the Mobile App as a web app. Since PB2017R3, the PS Web feature is now included as well a Mobile.
2) Configure your IE web browser for debugging ... https://www.appeon.com/support/documents/appeon_online_help/2017/powerserver_toolkit_user_guide/ch06s01.html
3) Use the Web debugger to step through your problem code. Most likely, your code will fail the same in a Web app vs mobile deployment. For example:
4) Once you locate the problem code and repair it ... deploy & test your Mobile App again.
5) For extra help in debugging Web/Mobile app issues, check the PS logs. Tip: Set "Development" or "Debug" mode in AEM for more logging information on your Web/Mobile App's execution.
6) For client side debugging, try logging to the App's local console. For example:
7) Of course, there is still the good old MessageBox() command as well.
HTH
Regards ... Chris