Cannot receive but can I still continue buying now and keep in my inventory (on PC)?

After reading that many ppl were 'grabbing' the Nova launcher, I decided to purchase (must be something good since so many droiders going gaga over it)

I have uninstalled it yesterday and revert back to touchwiz as the launcher seems to be taking too much resource (ram) until I cannot run my other apps properly. Most of the time they will load for a while then stop, even the camera could not work properly. At 1st I worried that kena virus or somnething but after reverting back to my default launcher, everything runs smoothly again.

I wonder whether I missed something or installed it wrongly or my phone (S3 unrooted) is not powderful enuf for Nova?