Fossify Contacts
★★★★☆
Basic, privacy-respecting contacts app for Android that works with all contacts accounts on your phone. Connects with whatever dialer and email apps you’re using. Will merge your view of contacts that appear in more than one account. Doesn’t send data anywhere else, which is more than I can be sure of with Google’s default Contacts app.
I use it with my Nextcloud contacts (synced through DAVx⁵) in addition to the handful I still have on my Google account.
The only problem I have with it is that when creating a new contact from another app “Add to existing” option doesn’t always work.
More info at Fossify Contacts.
Available from F-Droid, Google Play.