Looking for logging into the Salesforce One site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Salesforce One site. After that you can login as usual with your login credentials.
https://login.salesforce.com/?locale=eu
https://help.salesforce.com/apex/HTViewHelpDoc?id=sso_about.htm
https://www.onelogin.com/solutions/salesforce
https://rajvakati.com/2017/04/27/salesforce-sso-with-onelogin/
https://onelogin.service-now.com/kb_view_customer.do?sys_kb_id=KB0010375
https://onelogin.service-now.com/kb_view_customer.do?sys_kb_id=KB0010329
https://github.com/onelogin/php-saml/issues/303
https://docs.bmc.com/docs/remforce201701/administering/bmc-remedyforce-and-single-sign-on/configuring-single-sign-on/configuring-single-sign-on-using-onelogin/federated-single-sign-on-using-onelogin
https://chrome.google.com/webstore/detail/one-click-salesforce-logi/ckcjggdilfimmjnjmldgbbekigobcijn
https://support.talkdesk.com/hc/en-us/articles/115000293366-Talkdesk-Single-Sign-on
https://play.google.com/store/apps/details?id=com.salesforce.chatter&hl=en
https://itunes.apple.com/us/app/salesforce/id404249815?mt=8
https://help.salesforceiq.com/articles/sign-in-to-salesforce-inbox-using-single-sign-on-sso