This app and others like it are a great idea, unfortunately, due to restrictions in iOS for what an app can do, this app falls short with two major issues:
1. It drains your battery:
Over a 9 day period I tested using this app. Within the first few days I noticed quite a significant drop in battery life on my device and started to dig in. Although the developer claimed Moment uses barely any battery (around 2% of his battery usage), despite it having to use location services, I experienced differently. Using my phone an average of 3hrs per day I found moment was the app with the largest battery drain on my device, using 24% of my battery over the last 7 days.
2. The second major issue was more about the app not meeting my specific needs. I want an app that can limit access to specific apps. I use my phone for many productive tasks and really just want to limit my social media and other time wasting usage, but unfortunately this again is not possible due to restrictions from iOS.