Had to delete it. Too many ads. Very simple, and for the most part, mindless time waster. Could have been mildly fun, but the volume level and frequency of the ads completely spoils any calming effect the app has. Crazy pricing also. It's unclear if paying to remove ads is a one time thing or per stage. As a musician I found the tone sequences often unpleasant and ended in a musically incoherent way. When they told me I had to read and accept their TOS to play I was done. Bye!