＋メッセージ（プラスメッセージ） 42.40.3700

This release does not have a Play Store Description, so we grabbed one from version 54.48.0100:

It is a message application that can be exchanged only with a mobile phone number. In addition to exchanging stamps, photos, and videos, you can also enjoy group messages. You can also send and receive SMS.

Features of “+Message”
◇Simple and safe
・ You can start immediately without registering as a member!
・"Unregistered" is displayed for messages from people who are not registered in your contacts, so you can easily find them.

◇Convenience
・Can be used with the person whose icon is displayed in "Contacts".
・Up to 100MB of photos and videos can be exchanged.
- With the "read" function, you can see that the other party has opened the message screen.

◇Fun
・You can communicate expressively using stamps.

◇ Connect
・You can exchange messages with the company's official account. You will be able to receive important notices from companies, complete procedures and make inquiries!
・Customers can communicate with companies with peace of mind because official accounts of companies display the "certified mark" that indicates that they have been certified by DOCOMO.

■ Compatible models (supported models)
Docomo smartphones and docomo tablets with Android(TM) OS 5.0 to 12.0.
www.nttdocomo.co.jp/service/plus_message/compatible_model/index.html

■ Notes
・To use this service, an sp-mode contract, ahamo/irumo Internet connection service, and a contract that allows SMS can be used for MVNO (docomo line) use is required.
・This application requires a mobile data connection when using some functions such as initial authentication.
・If the recipient does not use this service, it will be sent and received by SMS (text only).
・ Packet communication charges will be incurred when using this application. We recommend subscribing to a packet flat-rate service.
・When using the service while roaming overseas, please turn on the "[Overseas roaming] + Use message service" setting.
・When using the service while roaming overseas, data may be automatically updated in addition to sending and receiving messages, so please be aware that packet communication charges may be higher than in Japan.
・When using the “Official Account” function, customers must conclude an official account usage agreement in a manner separately determined by the company that operates the official account.
・The contents of the official account and the customer's consent to use are outside the scope of our responsibility.
・Registration and setting of each official account may be canceled due to customer procedures such as MNP.