This post was published 1 year 8 months 27 days ago which may make the App / Game or info outdated. It is best to check the developers site to see if there is an updated version.

SpeakerPhone – Auto On v1.03 will automatically turn on your speakerphone. While the application is running, when an incoming call is received, the speakerphone of your device will automatically turn ON when you receive the call.
You can also automatically activate the speakerphone when you are making an outgoing call by checking the Outgoing ON in the menu.

It should work on smartphone and PocketPC WM5/WM6

NOTE: before executing the application, create these STRING values first using a registry editor :

HKCU\Software\SpeakerPhone\Auto with value = 0
HKCU\Software\SpeakerPhone\Delay with value = 5000
HKCU\Software\SpeakerPhone\USB with value = 0

Source : xda-developers.com

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SpeakerPhone – Auto On v1.03

Tags: auto answer, cell phone, freeware, Mobile, PDA, PocketPC, PPC, registry, smartphone, Speaker Phone, SpeakerPhone, Windows Mobile