: The free app includes ads that interrupt the learning flow.

: A "Premium Mod" claims to provide unlimited time , offline practice, and all topics unlocked without the monthly or yearly subscription fees. The Real Risks of Downloading Modded APKs

: Free users are restricted to just 5 minutes of learning every 10 hours.

The standard free version of Drops is highly restrictive, which drives interest in "unlocked" versions:

Security experts and community discussions highlight that downloading unofficial "v36 build" files from third-party sites is extremely dangerous: Drops App Review

: Topics must be unlocked one by one through gameplay in the free version.