Windows app to configure Raspbian SD card image before first boot
Setting up Wi-Fi on a Raspberry Pi with a display directly connected is usually easy to do in Raspbian. However, if you want to setup a headless Pi or connect to a university's enterprise network, this requires editing configuration files manually and is less straightforward. This app lets you set up Wi-Fi right after flashing an SD card image for your Pi while the SD card is still in your PC.
PiBootstrapper can automatically generate the Wi-Fi configuration for both personal and enterprise networks and also enable SSH (Secure Shell) login. After bootstrapping the Pi with this app, it should connect to Wi-Fi right away when it boots and be accessible remotely over the network without any further setup necessary.
This app is written in C# and only runs on Windows, but you can manually configure a headless Pi setup on Linux or Mac. See here for instructions on how to create wpa_supplicant.conf and ssh files on the SD card boot partition (also here if you need to configure wpa_supplicant.conf for an enterprise network). If you want to set up more than just Wi-Fi and SSH on the SD card image, try the cross-platform app PiBakery which allows all sorts of customizations.
Wi-Fi passwords are hashed by the app before storing them on the Pi rather than being written as plain text, allowing you to safely edit wpa_supplicant.conf in public without revealing your password. If you want to manually hash the passwords, you can use the wpa_passphrase command for WPA Personal networks, or see here for WPA Enterprise networks.