are there any other coins that have a halving coming or who just have halvings like ltc and btc?
LTC halving is pretty new to me. I know BTC halved to BCH, but not too sure if LTC also halved. Maybe Ethereum will halve too in future to Constantinople.
So far I'm not aware of any coins except Bitcoin and Litecoin if we are talking about block halving. Those two are the only coins so far that reduces the rewards miners do get by mining for those coins. Why those two? Obviously it was how bitcoin was design, and second Litecoin is a fork from Bitcoin. They just put some codes to difference the two, like the total circulating supply but not the block halving.