with the activation of SegWit and all the things it opened up there will be capability of creating smart contracts on bitcoin and by extension it will also be a possibility on other altcoins that are based on bitcoin and also have SegWit activated. coins such as Litecoin for example are going to be in that group.
ArtByte is in the SegWit activation period, and lays out plans in its roadmap to use new SegWit enabled technologies like MAST for smart contract implementation.
You can follow ArtByte's SegWit implementation here:
http://www.artbyte.me/segwitcsv-progress-tracker/