Function to get 'user agent' data

Though Appian has provided an ability to limit the concurrent logins, is it a good practice to refrain from concurrent logins(I assume that the solution in this case would be restricting the user to have only one login)?

I don't remember coming across any best practices about concurrent sessions. Every requirement is different and has different priorities. If something is OOB and the LOE is low and usually business wants to do it. Cases like this it's not just LOE but also other limitations as not allowing concurrent sessions to satisfy the business requirement. I follow as much transparency as possible so that my client can take an educated and right decision.

As Appian has an ability to access the application from multiple devices such as tablet, desktop, mobile etc, is it right to ask a user to log out from an device before starting to use another device?
This can be mitigated via setting up lower timeout: forum.appian.com/.../Post-Install_Configurations.html

Again, it depends on the requirement, if it's a hard requirement to capture the device used to make some decision this is a work around with limitations.

Though Appian has provided an ability to limit the concurrent logins, is it a good practice to refrain from concurrent logins(I assume that the solution in this case would be restricting the user to have only one login)?

I don't remember coming across any best practices about concurrent sessions. Every requirement is different and has different priorities. If something is OOB and the LOE is low and usually business wants to do it. Cases like this it's not just LOE but also other limitations as not allowing concurrent sessions to satisfy the business requirement. I follow as much transparency as possible so that my client can take an educated and right decision.

As Appian has an ability to access the application from multiple devices such as tablet, desktop, mobile etc, is it right to ask a user to log out from an device before starting to use another device?
This can be mitigated via setting up lower timeout: forum.appian.com/.../Post-Install_Configurations.html

Again, it depends on the requirement, if it's a hard requirement to capture the device used to make some decision this is a work around with limitations.