GET: SHUTTER SPEED APP for your phone.

For the next project (motion blur), you will need an app for your phone that allows you to control the shutter speed.

Here are a couple of links for ANDROID:

Android users. CLICK HERE.
This site (CLICK HERE) might have a shutter app for your phone.

Here are a couple of links for iPHONE:
iPhone user. CLICK HERE. 
CLICK HERE FOR OTHERS (iPhone).

MOST IMPORTANT FEATURE TO LOOK FOR: 
You want an app that will give you a range of slow shutter speeds (1/8", 1/4", 1/2", 1", 10", 30", 60", Bulb)

In the app, the shutter speed may not look like a fraction. It may just be a listing of the denominator of the shutter speed fractions. (ex: 250, 125, 60, 30, 15, 8, 4...).