Yeah there is similar function hear but it takes so long to get a correction on your notebooks and it's hard to compare your writing with the correction but in this website you can see each sentence correction beside the original one and it's much easier to understand it( at least for me)
and as it's just for writing of course  has better capabilities.

Hi, I organized an English club online that enables people to practice writing and reading.  Click my profile if you are interested in my group discussion. 

Thank you for recommendation. There is similar function on italki. 

How many users on that site?