The keyboard is badly designed. There is a triangle in the corner to show additional keys, which are not independent from the menu and the main keyboard for instance if you activate only the additional keys than to open normal keyboard for some input you have to close key-bar, open menu and open keyboard and then key-bar on the top of the keyboard re-appears which is ok but to close only the main keyboard again you have to repeat the whole procedure in reverse order.
Also author didnt think much about usability of a mouse. It is nearly impossible to do right click in the mode where screen dragging is locked. And whendragging is unlocked then the only practical use of the mouse is the right click.
There are some bugs, for instance if you return into app the lock shows that you have the screen dragging disabled but it is not true, you have to disable and re-enable the lock.
I would have rated the app a bit higher but I am dissapointed because the lite version lacks the full keyboard and mouse support so the customer have no chance to encounter the biggest flaws of the full version before purchase