It would be helpful if I could remember to do something that is connected to a specific place in the real world.
Have a small button you can place anywhere (magnetic, adhesive back etc.). You record a message on it like “throughout old stuff”, and place it where you need to do what you need to do. When you come close to it it will play back what you recorded.
NPS is important to measure but not easy to implement.
Add one line of code to you website (or a plugin for a CMS like WordPress) and get all the functionality. You can set multiple types of triggers (exit intent, timed, click a certain link etc.) to activate the button. Visitors can also just click the button. Set up is easy and you just have to click a few options to make it work on a domain and/or URL level.