You see the message as "Something's wrong, please try again later!" if the oAuth for V4S Mobile app is expired in your org.
By default, Salesforce allows the Sandbox oAuth token to be active only for one week. If you are using V4S Mobile in your Sandbox, you have to refresh the oAuth token every week to access the V4S Mobile. Sometimes the oAuth is active for less than 8 hours in Sandbox which is a known issue in Salesforce Sandbox org.
If you see the message as "Something's wrong, please try again later!" or a message as "Org license expired", please process the oAuth for the V4S Mobile application and then start using the V4S Kiosk application again.
The oAuth does not expire frequently in the Salesforce Production org. You should process oAuth only once upon installation and the oAuth is active for at least a year or until you revoke it, based on the limits set up in your Production org.
We suggest you install the V4S Mobile app in your production org as the V4S Mobile app does not affect any of your existing data in Salesforce. Additional data related to V4S Mobile Users, V4S Mobile apps, TimeSheet details, etc., get created in Salesforce when you install the V4S Mobile app in your org.
All these Tabs and data will be deleted if you uninstall the V4S Mobile application in your Salesforce org after testing. And it does not affect any other data in your org upon deletion of the V4S Mobile application.