MUTUAL CONTACTS

Plus Messenger provides displaying mark which shows is your contact mutual or not. Mutual contact is user who is added to your contacts list and who has added you to his contact list.
This mark is displaying in your Telegram contacts list (App menu - Contacts).

To turn mutual contacts marks (👤) ON do the following:
1. Open your contacts list: App menu » Contacts. If there is no "Contacts" in your app menu then turn them ON in App menu » Plus settings » Navigation drawer » Show menu options.
2. Tap on Contacts list screen header.

See screenshot here.