How do i download my library card to my phone
Do you mean you would like to save an image of your card on your phone so that you don't need to carry the card with you? If so, simply take a picture of the card (the side with the barcode on it) with your phone. It will be stored among the other photos on your phone.
Or do you mean you would like to be able to access your library account on your phone? There is an app for that! It's called MyOPL, and it's free--just look for it in the app store or wherever you normally get your apps.
In addition--a colleague reminded me of something else. If you download the app, you can also bring up an image of your barcode by clicking first on "More" (down in the bottom right-hand corner of the screen) and then clicking on "My library card barcode." That also gives you an image of your barcode on your phone, so that you don't need to carry your card with you.
I hope this is what you meant--if not, please let us know!