LPT: Want to stay disciplined about losing weight? Take selfies of your physique over time, AKA progress pics.
Taking selfies of myself after every workout and then watching my waist shrink from week to week has been extremely motivating, and I enjoy getting closer to the day where I can compare a before and after picture of myself and see major progress. I think this method has played a big part in helping me stick with my workouts and diet over the past 4 months of my journey (I'm down 30 lbs already). It also applies to those who want to gain weight, get more toned--any goal around how you want your body to look.
Right now, I’m using the Youday app to organize my progress pics (after importing all the existing ones I took) and easily generate a before vs. after comparison picture. It’s the most simple and clean progress pic app I’ve found for iOS so far, but I’m sure there are other tools out there that work better for other people.