So I’m new to watching Thai drama I know there’s an app called Viki for Korean, Chinese and Japanese dramas but is there any app or website that where I can watch dramas from Thailand. 

Hello! So, I usually watch Thai dramas on lots of different sites (depending on  availability, etc.), but I did find a site you might enjoy using. 

Sorry if that doesn't help! 

Here are the sites you can watch Thai drama

Jasminlakorn blogspot

Justanothermuse

Ohsweethaven

Neko meow meow

Kissasian

Most of them  have links where you can stream n download

Some of Thai Drama on Youtube from GMM25 and Nadao Bangkok have English subtitles. You can try searching for "Project S the series" and "In family we trust". 

Ch3Thailand, One31, Channel 8, PPTV and few others usually put their drama on Youtube too. However, there is no English subtitle provided.