The Financial Conduct Authority (FCA) is the financial regulator in the UK, responsible for overseeing all firms that provide financial services directly to consumers. Unlike in many other countries, the FCA is fully independent from the government, and is funded by fees collected from its members. The FCA is a highly experienced regulator that oversees a large number of forex & CFD brokers, many of which offer web-based trading platforms of some sort.
Some of the web platforms offered by FCA-regulated brokers are simply web-based versions of traditional downloadable platforms, while others are built from scratch for the web. Whichever web platform you choose, the main benefit remains the same, which is that the platform can be accessed on any device as long as you have a working Internet connection.