On Samsung devices below S4 (yours is an S3), PRO has problem with Touchwiz, the Samsung home screen app.
The only way you have to play is to flash cyanogenmod on your device following this tutorial -> https://wiki.cyanogenmod.org/w/Install_CM_for_i9300
If you are not an expert android user, don't try installing cyanogenmod because it would be difficult and dangerous.
I have cyanogenmod with Smart launcher 3!