テザリングオプションアプリ is an application developed by ソフトバンクモバイル株式会社 that allows users to utilize the tethering option on their smartphones. This option enables users to use their smartphones as mobile Wi-Fi routers. However, it is important to note that this application is not supported on Android 5.0 or higher, except for Xperia Z3 which can still be used on Android 5.0 or higher.

The tethering option is an optional service for customers who use 4G smartphones. It allows them to use their smartphones as mobile Wi-Fi routers. However, if the amount of data used each month exceeds a predetermined limit based on the customer's contract, the communication speed will be limited to a maximum of 128kbps for sending and receiving data. To use the tethering option without any restrictions, customers need to sign up separately and there may be additional charges.

Please note that the proper functioning of the application may depend on the user's environment and external connection equipment. When using tethering with Wi-Fi connection, it is recommended to set a password to prevent unauthorized use by third parties. Additionally, the application performs automatic communication by regularly connecting to 3G/4G, but this communication is free of charge. It is also important to consider that the use of Wi-Fi may be limited depending on the country or region, so it is advised to check the laws and regulations of each country or region before using the application.

Overall, テザリングオプションアプリ is a useful application for those who want to utilize the tethering option on their smartphones. However, it is important to make sure that the application is compatible with the user's smartphone and operating system version.