Onlinepbx-softphone is an Android app developed by Tesla Telecom LLC, available for free in the Business & Productivity category. To use the app, you need to create an account on the onlinepbx.ru site, create a sip user, and log in to the application using the sip-id obtained in step two.

Once you're logged in, you can make and receive calls, listen to recordings of conversations, forward calls to a colleague, create new contacts within the app, and import contacts from your phone book. You can also go to the amoCRM contact or deal card, and go to amoCRM to create a new contact based on received calls. Additionally, you can turn on the "do not disturb" mode and contact technical support if needed.

Overall, Onlinepbx-softphone is a handy app for those who need to make and receive calls on the go. However, keep in mind that you need to create an account and a sip user before you can start using the app. For any feedback, you can reach out to