📝 Update documentation

README.md

@@ -23,6 +23,12 @@ Apps view allows sorting results by :
 index, name, category, install count, score, size, last update date, price, presence of advertisements,
 presence of in-app purchases, minimal android version requirement and permission count.
 
+Additional info is available as tooltips :
+ID on index, editor on name, rating count on score, relative time on last update date.
+
+Apps are guaranteed to be available from the Play Store, but additional links are generated :
+[APKPure](https://apkpure.com/), [F-Droid](https://f-droid.org/en/), and [Aptoide](https://en.aptoide.com/).
+
 | ![](https://i.goopics.net/1jeg1h.png) | ![](https://i.goopics.net/klhane.png) |
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