I have a project that requires many people working together on a large flowchart with a few thousand entries. There are many flowchart software (or website) out there but is there any that allows you to work together as a group like google docs does without having to save and send updated copies to everyone every time someone makes an edit? Also, preferably free.
Did you test the Google Docs "Draw" app yet? It also supports creating flow charts.
https://www.lucidchart.com/ has a good colloborative offering. They have a free version, but limited. They also allow you to connect it to Google Drive.