How to fix mobile login session

Some asked 

I noticed that on mobile, the session expires fast and log user out immediately but on pc it's not the same, i want my users on mobile to not be logged out just like the pc version does. Please how can i do that? 

I believe I found a solution for this. Well! It's working for me.

Backup your file before changing anything.

Open bootstrap.php and look for

$user->log_session(); 

And replace with

ini_set("session.cookie_lifetime", 604800);
ini_set("session.gc_maxlifetime", 604800);
$user->log_session();

This piece didn't work on mine.  As I'm trying to log on and site didn't log me in 

who else has tried this tutorial? 

works