Request for update

If you set WP_Debug to true you get deprecated warnings related with obsolete capabilities.

you sould update

add_menu_page("Simple Parse Push Service", "Simple Parse Push Service", 'subscriber', "Simple-Parse-Push-Service", "simpar_admin");

with

add_menu_page("Simple Parse Push Service", "Simple Parse Push Service", '1', "Simple-Parse-Push-Service", "simpar_admin");

https://www.ads-software.com/plugins/simple-parse-push-service/