I am using a PicsArt photo editing mobile application to use REST Services to provide functionality. It is also multilingual and depends on the current device language. How can I submit the language parameter in the OAUTH URL and then read that parameter to open the Login page in the respective language (English / Spanish and Portuguese).

I am using a PicsArt photo editing mobile application to use REST Services to provide functionality. It is also multilingual and depends on the current device language. How can I submit the language parameter in the OAUTH URL and then read that parameter to open the Login page in the respective language (English / Spanish and Portuguese).

Can we create some game app through Salesforce or is there any gaming app already available on Salesforce App exchange?