This can be easily achieved using a nested inner join, for your example this would be:
SELECT * FROM (application_table INNER JOIN appxserv ON application_table.id = appxserv.app_id)
INNER JOIN service_table ON appxserv.serv_id = service_table.id
WHERE appname = "app1"
You can change your WHERE statement to use id's or something as well ofcourse.