YouMail is a alternative to the iPhone's built-in visual voicemail. It lets you listen to your voicemail on any device, computer, or email account. It also has a much a more sophisticated caller ID that includes the caller's name and location.
The above mentioned features are available for free, but for a monthly fee, you can have your voicemails transcribed into text so that you can read them instead of listen to them. This transcription is human-powered, so it is extremely accurate.
If you were to ask me what I use my iPhone for, I'd spatter off at least ten different things I regularly do, but "to make calls" would not be on the list. Needless to say, I hate voicemail and would much rather someone text me than leave me a voicemail. In fact, I rarely actually listen my voicemail and instead just shoot the person a text asking what's up.
I need a YouMail subscription.