I emailed The Reading Club app developers because I wanted to verify my comment above, and they gave me a lot of info. They confirmed it's currently 5 cents/month on Android for people in Ukraine (your phone knows were you are, apparently), and the Apple App store offers people in Ukraine a promo code ("READFREE") to have unlimited access for 1 year for free. (Most other places it's 50 cents to 99 cents per month).

I'm told that they intend to create similar free / nearly free opportunities for any location where school is disrupted by widespread violence/war/conflict (such as Afghanistan, Tigray, parts of Myanmar, etc.). If you know a place that ought to have that benefit, email them: contact@thereadingclubapp.com.

One shortcoming for use in conflict-affected contexts is that the app currently needs Internet to function properly (and Internet is often unreliable in these settings) but the development team says this will soon be changed such that the app will be able to operate just fine when wifi is unavailable (their reading library will download when the app installs).