Phone OS rated = security * flexibility) on scales of 0.0 through to +1.0 Maemo5 (= 0.9 * 0.8) UbuntuTouch (= 0.7 * 0.5) Apple (= 0.6 * 0.3) Android (= 0.4 * 0.6) Tizen (= 0.2 * 0.1)