Usable! ⚠App is good but it doesn't provide pin or other locking facility. ⚠If I lock it using other app viz. app lock it works partially (i) it ask for pin or pattern when attempted to open. (ii) But when minimized (closed) without entering pin or pattern  in recent tab authentication code can be seen easily. ⚠So it doesn't provide good security  instead I use LastPass authenticator which gives all this features.
August 19 2016