I've been looking for a decent todo list manager for ages, but everything always seems to be a separate list or program and I really wanted something that would be in my face and embedded in something I look at every day, like my calendar or email. This morning I came across this article on Lifehacker and decided to install the app.
http://lifehacker.com/hashtagtodo-turns-google-calendar-into-a-to-do-list-1728186314
https://www.hashtagtodo.com/
It seems to do exactly what I want it to do and might well become my go to app for todo lists. I have been impressed enough with looking at it this morning that I decided to post it up for people to look at. Highly recommended (at least at this stage).
Missed this post first time round, going to give it a try. Anything to not have to go outside Gmail and Calendar and into 'another' application.