This is a very cool website i found that will improve your rapping and freestyling!!
RapPad is a website that helps you in every aspect of rapping, from writing lyrics to creating beats to freestyling.
The write tab is a place where you can write down your raps and with every new word that you place on the above box pops ups suggested words, you can upload your beat to listen to while you write it so you get a feel for your rap.
You can explore others work in the explore tab.
The freestyle tab in my opinion is the best part of the website, you can customise the time that a new word gets thrown at you, the type of words and the beat. They provide sentences and words that will work and rhyme with the current word you are provided with.
They other tabs include battle and beats and forum, all very good tabs that play music, watch previous battles and look at trending threads.
For the full experience i suggest that you go ahead and check it out for yourself.