Today, I haung out with my friend and used my smartphone for only for a short time. Today, I hung out with my friend and used my smartphone for only a short time.

hang should be past tense.

Today, I haung out with my friend and only briefly used my smartphone only for a short time. Today, I hung out with my friend and only briefly used my smartphone.

Hang should be past tense.

I think screen time and daily fulfillment of the day are in an inverse proportionrelationship; the more you watch the screens, the less you enjoy the day. I think screen time and daily fulfillment are in an inverse relationship; the more you watch screens, the less you enjoy the day.

I think "in inverse proportion" is also correct. I simply changed it because I hear "in an inverse relationship" more often.

I think screen time and daily fulfillment of the day are in inversely proportional; the more you watch thelook at screens, the less you enjoy the day. I think screen time and daily fulfillment are inversely proportional; the more you look at screens, the less you enjoy the day.

I keep in mind to not to use my electronic devices for no reason. I keep in mind to not use my electronic devices for no reason.

I keep in mind not togo out of my way to not use my electronic devices for no reason. I go out of my way to not use my electronic devices for no reason.