Finding a place to live in Ann Arbor can be a very real challenge. There are many apartments, condos, and rental houses available of varied size, quality, location, and especially price (most often expensive!). A very helpful website is the U-M Off-Campus Housing website. You can search for available housing, leave a personal ad, search ads there for possible roommates, and find other information.
Often, those involved with GradCru will write a short ad saying they are looking for roommates or apartment space that they post in the GradCru GroupMe app.