Googles has a million , but have not used it so can’t tell you anything about it. used the phone app version that was free but not with anything of value.
simply put I built my own data structure using Graph databases that run local and they are my unlimited long term memory for my personal gpt client. you can find it in the forums called kruel.ai. it can take voice inputs, has its own message application , has a doc ingester to fill out its brain with manuals etc. its still in development and has been running for almost 2 years. It even use to play games and twitch stream with me and my followers and remembers them all etc. uses the GPT3.5 model to keep the costs fractional so I can chat with it all day on my data and have only spent less than lunch 
The next version 6 will have more understanding and its approaching LLM stacked on openai GPT. Using Machine learning and the likes. my Discord link in the forums goes to my project where I discuss changes I did with out giving away everything but you can see from the start all the way through each memory revisions changes and choices I made to get to where it’s at. took less than a few months with V1 and 2 years to get to start ov V6. V5 currently runs but is not the cheapest and smartest way to do it, which is why the next version comes in giving it machine learning and embedding with relational points like a neural network.