GrpTalk
An app-based solution that is downloadable on iOS, or Android, GrpTalk facilitates audio conferences by permitting you to either have an immediate call with your contacts, or a scheduled call for repeated conferences.
Among its many noted features for the same are the ability to work on mobile and landlines with equal ease, and the host requiring internet only to initiate calls. One of the main drawbacks to this however, is a delayed start for group calls; the user will have to wait 30 seconds to initiate conversations.
UberConference
From the American company Dialpad, UberConference is another solution that strives to simplify and facilitate voice calls for business users. With the basic service to host calls free of charge, calls can be initiated without any PIN.
The app also has a website variant to initiate the conference calls, with the ability to customize features such as hold music, screen sharing, and more.