The short answer is no, you need to use App Inventor through a web browser and with internet access.
However, App Inventor is an open-source project, which means you can download it to your computer and run it from your local server. There is no easy way to do this and it is a very complicated and technical process. If you are considering trying this, here are some things you need:
- A computer that is running MacOSX, GNU/Linux, or Windows operating systems (This will NOT work on a Chromebook)
- Internet connection
- Understanding of how to work and debug errors in the command line
- Understanding of how to install packages in the command line
- Understanding of git
If you are interesting in trying it, here's a good place to get started: How to build App Inventor from the MIT sources. Keep in mind that the Technovation team does not provide support for technical issues you may encounter, but there are some good sources and videos online that may help you.
The easiest way to to use App Inventor is through a web browser and with internet access. If you need to work offline on your code, try planning things out on paper by making a paper prototype or a flowchart!