Calming Bottles can be used by children on the autism spectrum to regulate their emotions during a timeout period. This App provides a useful alternative to making your own, and allows you to set the colour of the glitter and the time that the glitter takes to settle on the bottom. When the glitter has settled, the timeout is over.
Instructions for building your own Calming Bottle can be found here: http://blog.theautismsite.com/calmingbottle/
Please note that the developers of this App are in no way affiliated with the blog linked to above.