Available on iPhone and Mac. Opal lets you block distracting apps so you can you don't spend all day scrolling.
Use the promo code for 20% off your yearly subscription for Opal Pro at checkout on the website. Works on existing and new accounts.
Or, use the referral links to get one month free if you want to try it out first.
There's also some other promo pages on their website which might be worth trying too:
* 30% off for Black Friday
* 50% off for students
Seems like another example of an app needlessly being a subscription. Also don't iPhones already have a focus mode??