Likely talking about mobile app, website works quite fast on mobile devices as well as computer. We are reiterating some performance related issues on Mobile app and communities navigation being simplified as well.

As for website, editor offers your community list as soon as you type on tags input also you can click on any community tag from post or Communities page https://ecency.com/communities and start posting to that community. Our next major update on website will have improvements on communities related operations and making community creation easier. Stay tuned for that.