A free app for Android, by 株式会社ケイ・オプティコム.

With LaLa Call, you can make free phone calls to other Android applications while also enjoying traditional chat features.

The app has a simple and intuitive design, and the main menu is easily accessible from the home screen.

This app lets you synchronize your phone book contacts so that you can enjoy the following features:  sending media content such as images and videos in group chats, a refer-a-friend feature, toll-free 050 calls, customizable ringtones, an answering machine with recording command, mute, speaker and hold controls, and stamps.