People who feel connected to their future self treat them better
This is the closest thing to a foundation this app has. In work led by Hal Hershfield, people shown age-progressed images of their own face went on to allocate more money to their future — the effect runs through how connected they feel to the person they'll become, not through motivation or willpower. Feeling that the future you is genuinely you changes what the present you is willing to do for them. It is also, plainly, why this app renders your face rather than a stock photo.