People use the Apple Wallet app for a lot of different things. People put their credit and debit cards in it, sporting event tickets, concert tickets, airplane tickets, subway passes, etc.
It would appear that the next thing that people will have another reason to use the Wallet app. That thing is going to be your YMCA membership.
In a video posted recently on YouTube, it shows someone who has been able to test the ability to use a YMCA membership card on the iPhone and Apple Watch. The reason for both of those devices are that they have Near Field Communication (NFC) in them.
You can also see in the video that this feature would work on Android smartphones too.
Right now, the only option that YMCA customers have to do something similar to this is through its YMCA Membership Passes App in the App Store for the iPhone and iPod Touch.
The YMCA has not said anything about or whether or not they are going to be giving it as an option to their customers, but since this does appear to be in development, it could be a sure thing that the group does plan to release it to the public eventually.