Hi Juan,
I’m using Ultimate To-Do List. Here was an article I wrote about that app and another one that I had considered:
To be honest, I rarely open the app. I do, however, frequently send emailed tasks into my system using another app I wrote about recently, Email Me Pro. I put a shortcut onto my home screen with the email address pre-filled:
https://www.40tech.com/2012/02/14/app-of-the-week-email-me-pro-android/