check.in
checkin.com
checkin.net
checkin.org
checkin.co
checkin.io
checkin.us
checkin.at
checkin.nz
checkin.be
checkin.cl
checkin.se
checkin.si
checkin.ею
checkin.ua
checkin.рф
checkin.co.us
chec.ki/n
ch.ec/kin
ch/eckin

.ch

Learn more about .ch at IANA or Wikipedia, or view all top-level domains.