The fact that I can connect my website or app directly into an electronic SIM card without having it installed onto any computer makes this product amazing! This feature has been very helpful for me because now there isn't anything else required when launching new products (or even just updating features). There are many different types available; some people prefer them all but personally speaking i like how easy they are to use since you don’t have much technical knowledge needed to implement these cards yourself. So far nothing negative about celitech api so would definitely recommend anyone looking into getting one. It was super simple adding our code straight out from google docs which made things alot easier than doing everything manually ourselves through creating accounts etc..