iPhone has had this since iOS 17, and my Samsung has had this feature for a while too. Not sure about other androids, but you probably just need to enable it.
Tmobile does it as a service but it's a paid one and inconsistent in accuracy. I had it for free as part of a plan for a while and told them no thanks to an additional charge. Not sure it's worth paying $5/month.
I haven't found any voicemail services I really like, so I'm thinking of building my own thing using Twilio and OpenAI. Call comes in, Twilio calls webhook on my server, server opens connection to OpenAI using their new streaming API, sends call to OpenAI to build transcript in real time, uses OpenAI to summarize transcript and extract the person's name, number, and the reason for the call, sends me an email with the contents and a copy of the message attached.
I have a boss who sends the most rambly incoherent emails I've ever encountered from anyone. Yet when he sends a text (It's really WhatsApp but same difference) it's basically four words.
People do not really like typing on phones so they tend not to leave long messages
It’s summarized an any “stack” of notifications. So a bunch of messages from the same group chat, or a single app sending you a bunch of notifications, etc.
I’ve only been trying it for like 48 hours, but so far I’m impressed considering this is a local LLM running on my phone.