What services/programs/applications exist to work together to create site prototypes (and other schemes, for example, business processes)?

Question

Layouts and prototypes

Requirements:
1. You can draw website interfaces
2. You can draw mobile application interfaces
3. You can draw business processes
4. You can draw anything with a marker like on a whiteboard
5. You can put and fix your picture as a background (for example, a Bootstrap grid of a certain size).
6. Real-time work - each team member can see how other team members draw, that is, the process itself is visible, not the final result ...
7. Some team members watch this process from the iPad.
8. Some of the team members draw these sketches from the iPad.
Now I use cacoo, the service is not friendly with the iPad, otherwise it suits.
Questions:
1. Is there at least one service that would meet my requirements (and be better than cacoo)?
2. I saw other services, some of them I liked, here they are:
mockups.me/,
uxpin.com/,
https://gomockingbird.com/.
Do they allow you to work in real time?

Answer 1

To jointly create business process diagrams, you can use https://storm.bpmn2.ru