You are describing the behavior of an app using either the CloudDB or FirebaseDB David or possibly using a shared GoogleSpreadsheet on Google Drive.
Something here might help get you started:
Firebase Chat and Label HTML Content
Tutorials and Guides
firebaselabelhtmlcontent
6d - Here is a demo showing how to set up your project to use firebase as a chat store, and demonstrates how the new Label HTMLContent property block can be used to good…
Sharing informations
MIT App Inventor Help
chat
5d - You might use the CloudDB or the FirebaseDB components to create a Chat app. Is that what you want to do Maddu? Antonio shows you two ways to…
FAQ Section: FireBase
Frequently Asked Questions
faqfirebase
Jan 1 - …VwbOYkXCual8I1JIBLCHhnCcgHj6N_Cfnlb4A/edit#heading=h.37rrxtruvui0 Brief Intro to Cloud Data and the FireBase Component - HAL https://rominirani.com/tutorial-mit-app-inventor-firebase-4be95051c325 Firebase bus…
Leaderboard and uploaded image
MIT App Inventor Help
Dec '19 - …database folder with Pictodrive, then I save name and image id in TinyDB. After the game, I save on Firebase the score as value, and the union of name and image id as tag. I m
To get specific advice, you might show us what YOU have tried so far. Exactly what you do depends highly on what the ‘file’ is and where it is located on your device. Is it a text file, an image, a sound file? There are limits as to the size and types of ‘files’ that can be exchanged using these tools.
Here are some resources to help you learn to use the AI2 tools A very good way to learn App Inventor is to read the free Inventor’s Manual here in the AI2 free online eBook http://www.appinventor.org/book2 … the links are at the bottom of the Web page. The book ‘teaches’ users how to program with AI2 blocks.
There is a free programming course here http://www.appinventor.org/content/CourseInABox/Intro and the aia files for the projects in the book are here: http://www.appinventor.org/bookFiles
How to do a lot of basic things with App Inventor are described here: http://www.appinventor.org/content/howDoYou/eventHandling .
Also look here http://kio4.com/appinventor/index.htm and here http://www.imagnity.com/tutorial-index/ for more tutorials.
Regards,
Steve