I cant install Telegram due to Snow Leopard V10.6 and it has to be 10.7 and above. My friend urge me to install Maverick which is free and therefore can install Telegram. Questions: How long has the free program Maverick has been out? If its free, why should people still pay to upgrade their Snow Leopard to Lion or Mountain Lion. Where's the catch? Do anyone experience any bad issue with Mavericks? I'm afraid after upgraded, my files or program may go haywire. I read from some review there are people regretted after installing, yet many are equally happy.