Are there any apps or methods to sync saved wifi between Android devices? Basically it would remember the wifi name and password if you logged into it once from one device on all devices synced.
Wifi credentials are actually not stored very securely at all, (plain text!), but in a system folder, meaning that only a rooted app could access it. Google's backup is your best bet.
It's stored in the
data/misc/wifi/wpa_supplicant.conf file, for the record.
This feature is built into Google Services, although my experience is that it sometimes struggles when moving to a new device or if you have multiple devices.
On the device that has the Wi-Fi Settings you want to keep, go to
Settings -> Backup & reset there is a
Back up my data option which includes
Backup application data, *Wi-Fi passwords*, and other settings to Google servers.
Other applications might have a hard time doing this as I would expect Wi-Fi credentials to be securely stored, like passwords. That might mean root enabled applications can do it but I do not know of any.