Bubblet

From the developer's website:

Watch your clock, this game is fascinating!

Bubblet is an easy but fascinating logic game. Match as much Bubbles as possible in order to burst them. The more are aligned together, the more points your get!

Choose between four game modes:

Standard:

Try to remove all Bubbles, if possible. Vertical gaps will be closed by the Bubbles when falling down, empty columns will be closed by the other columns with will move next to each other. The game is over if there are no more Bubbles which can be removed. If you do have five or less Bubbles left at the end, a "Bubble Bonus" will be awarded according to the number of Bubbles.

Continuous: (default setting)

This one is like the Standard mode, but empty columns will automatically be refilled from the left side of the board. Because of this you will never be able to have less than five Bubbles left if the game is over, and so you won't be able to get a Bubble Bonus here. However, using this mode you should easily be able to gather more points than using the Standard mode, because the game itself will last a lot longer.

Shifter:

This mode also is like the Standard Mode, but the not only the vertical gaps will be closed by the Bubbles, but also the horizontal ones. This mode is a bit more challenging as the Standard mode, but because of the additional movement of the Bubbles you'll a quite more compact field, which is much more easier to solve if you first got used to it.

MegaShift:

MegaShift is the mode for the professional. It is a combination of the Continuous and the Shifter modes. This means that vertical as well as horizontal gaps will be closed and empty columns will be refilled from the left. But the new columns won't last long as they are, because those Bubbles will also move to close horizontal gaps. Looks a bit confusing at first, but later you'll love it, and I'm sure it will be the mode of your choice most of the time because of its compact field and theoretically endless gaming fun.