Something went through my mind today. That's Rake Chat. This is the tool that looked promising. I bought it and tried it, and the app was doing fine. But, the devs were unwilling to listen to users' feedback, which was sad. Then, they left Appsumo and went to raise funding for their project. They were not making it. Finally, they have closed down. I think they failed because they didn't listen to users' feedback.

This is a good example. You must listen to users' feedback and make changes accordingly when you are new. If you are stubborn, you will have the same fate as Rake.ai.