Rule 1: Every app evolves until it does messaging.
Rule 2: Every app will eventually add “updated and synced across all your devices” to its list of features.
Rule 3: Every app will at one time have the tagline “x. Reinvented” (X being what the app does).
Rule 4: Every app made by VC-backed companies in Europe and US will make an iOS app first, regardless of the size of the Android market.