About a week and a half in is a great time to call. You might want to call in the late morning. When I worked in a coffee place, the managers were always there during the busiest hours, which is the early shift. In the early morning, they’re setting up for the day and dealing with the morning rush. Then there’s a mid-morning lull before the lunch rush, which was when we took care of nuts and bolts things like hiring and paperwork.
There are different ways to call about an application. Some people would just call and say, “I’m calling to check on my application” or something like that. Um, thanks? I’d rather hear an applicant say something like, “Hi, I’m (name,) and I’m calling because I’m still very interested in this position. Have you had a chance to look over my application?” If you really want to be proactive, ask if there’s a best way to get in touch with the hiring manager, like an e-mail. E-mail is a great way to talk with hiring managers, because they can look over your messages when they’re not busy and they’ll be in a better frame of mind.
Good luck!