Question: After renaming my heroku app from the heroku website, whenever I cd to its directory in a terminal and run any heroku command, I get `App not found`. Does anybody know of a way to remedy this?

Answer: 
The Answer by James Ward is also correct, alternatively try doing this:

1). open a terminal

2). Go to your\_app\_directory/.git/config

3). Once you open the config file then edit as follows:

Change

```
url = git@heroku.com:old_app_name.git

```

to

```
url = git@heroku.com:new_app_name.git

```

Obviously substituting your apps old name to its new name. Hope it helps
Also checkout this link [renaming from cli - heroku](http://devcenter.heroku.com/articles/renaming-apps)
James Ward's solution didn't work for me. I had to enter my git url in a different format:

```
git remote rm heroku
git remote add heroku https://git.heroku.com/appname.git

```