A little over a year ago I was fortunate to make it onto the beta testing team for Beeper. TL;DR Beeper is a unified chat application (i.e. all major chat applications, including SMS, in one app). Beeper recently announced that their basic service is now free https://blog.beeper.com/p/beeper-is-now-free. However, they will be slowly working their way through a wait list. The convenience of this service can’t be understated. Also, encrypted services such as Signal are supported. Just go to https://www.beeper.com/ and click the ‘Get started’ button to join the wait list.
from the Play Store screenshots, it looks like it still sorts messages from different services into different tabs, doesn’t it?
I miss Disa. it uses to let you use SMS, Facebook Messenger and Whatsapp (and I think Telegram?), and you could merge conversations at will, which means that you could get all messages from a contact in one conversation view, regardless of the service it came through.