It's a great English-Polish dictionary and available on the portal PONS for over 600.000 translations from English into Polish and the same from Polish to English. In addition to standard translations, the dictionary PONS also includes colloquial and regional language variants of vocabulary use. The undoubted advantage of the dictionary is a very orderly way of providing information. PONS also has a very readable version for mobile phones - https://pl.pons.com/specials/apps.
If you are an app freak, it's good to use different applications to learning English too. I will show you many handy apps to keep learning English in a few minutes. Furthermore, I will show you many online dictionaries and websites to learn languages.