This is a pretty good application
Simple and user friendly. Better if English version is available, though.
"Rakuten mail" is a free e-mail service for the application which you can use the Contact your customers Rakuten mobile. It offers the domain of "@ rakuten.jp".
Simple UI, phone book application that developed the nimble operation concept
The Best Dialer, Caller ID & Block Spam, Call Recorder, Phone Book & Contact App
The contacts, dialer, & call log app that organizes your contacts & blocks calls
Use Truecaller to identify unknown calls, and block spam calls and spam SMS.
IP phone app that 60 percent cheaper call charges of smartphone "SMARTalk"! I use the 050 number at 0 yen monthly basic fee.
This application is an application for safe use with a simple procedure the Mobile Choice / Mobile Choice 050 / mobile call recording, etc. services.