Hey! So, I was using Repl.it the other day and the internet was terrible and it kept crashing the site and it would almost never save. So I think that you should have an offline editor. That way, you can edit your code easily without the website shouting errors at you about how you aren't connected.
Adding onto that, I think that it would be great if you had a Chrome App so that way you could go in, have it sync your programs and their code, and then it would let you edit it all there. And then when you want to leave, it just syncs your code again and updates your profile with the latest programs and code!