Translation:I downloaded many games.
I'm sorry mate. I was wrong. I checked the standard pronunciation.
Zai3 is only used when it means year, such as 一年半載. But it's not used often, kind of old Chinese. The rest are all pronounced zai4.
But, oral speaking if you say zai4, we'll think it's very weird.
Does it depend on where in the Chinese-speaking world that it's used (e.g. PRC (普通話) vs Taiwan (國語))? Some tones are this way. E.g. 法國 "France" 的“法” is 4th tone in Taiwan, but 3rd tone in PRC.
Not really, I checked the Taiwanese system. It says zai4 is correct. But one thing have to know, the government adjusts the standard pronunciation every several years, but it's not corresponding to the way we walk.