You can continue to contact the Chime sitters you've worked with through the Chime app or website until late June.
After that date, you will be able to find previous sitters you worked with by accessing your Bookings tab within your Sittercity account. All of your previous Chime bookings will be listed under the "Past" tab within Bookings. From there, you can find information on sitters you worked with on Chime, and contact them through Sittercity.
Please note that you'll need to sign up for a Sittercity account if you do not have one in order to access your previous Chime bookings on Sittercity. This must be done using the same email that you are registered for Chime with.