About this app
Practice in English grammar by filling the blanks in the real communications between the pilots and the air traffic controllers. 7 themes and 700 individual tasks are available, which cover the basics of English grammar: to be, to have, simple tenses, progressiveness, perfect tenses and passive voice. The app is based on the method, developed by B.Ya.Slipak, PhD.
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Sep 26, 2026 · 12:41 PM Free
Screenshots
