I've been using monicahq - personal relationship manager webapp:
Monica is an open-source web application to organize the interactions with your loved ones. We call it a PRM, or Personal Relationship Management. Think of it as a CRM (a popular tool used by sales teams in the corporate world) for your friends or family. This is what it currently looks like:

There's also an Android app chandler That is still in development but already supports bunch of features:
Chandler is Monica's official mobile app. Monica is an open source personal relationship manager available as a web application. While the web app has many features, the mobile application currently has a limited set of features. It lets you read your data from your web account.
It's also FLOSS (GPLv3) on Github: https://github.com/monicahq/monica
As well as on Patreon: https://www.patreon.com/monicahq