How to indicate container is scrollable without scroll bars

In Android I'm trying to work out a way to indicate to the user that a container can be scrolled. I'm not a fan of scroll bars and usually turn them off for all containers but would enable the fading edge to indicate that a container was scrollable. In Android 4.0 and beyond though, the fading edge no longer exists.

What would be another way to indicate to a user that a container is scrollable without using scroll bars, and without the ability to use a fading edge?

I've tried using arrows but it didn't make much sense from a user standpoint and a gradient in the scrollable direction didn't exactly jump out as meaning something was scrollable to me. I've also tried having a bit of the content show at the edge of a scrolling container to indicate that there was more information but it's not very reliable that something will overhang with the different screen sizes and the amount of content per container.

Here's an example of what I'm trying to indicate.

In this 3x4 grid, how can you indicate to the user that the container can be scrolled beyond the 12 items that are on the screen? In some situations there will be content overhang but this is the situation I'm trying to account for.

Also, the grid is just an example. My content is a single, horizontally scrolling row of icons.