Save contacts - Save contacts app provides features through which users can select the desired data to create the backup in a variety of different formats.
iMyFone iTransor for WhatsApp - iMyfone iTransor for Whatsapp is the best transfer tool which can help you transfer Whatsapp cross-device.
My Contacts by Captain Tushar - My Contacts is an app by Captain Tushar that comes up with features to help you in managing your contacts list so you can effortlessly delete or edit existing contacts.
Jihosoft WhatsMate - Jihosoft WhatsMate is an all-in-one WhatsApp manager for both Android & iOS users. It enables you to backup&restore WhatsApp, recover deleted WhatsApp data, and transfer WhatsApp files between Android and iPhone.
SMS Backup+ - Backup Android SMS, MMS and call log to Gmail / Gcal / IMAP - jberkel/sms-backup-plus
iMazing - iMazing lets you transfer music, files, messages, apps and more from any iPhone, iPad, or iPod to a computer, Mac or PC. Manage and backup your iOS device simply without iTunes. (was DiskAid)