@nanu-c I'm at Purism and have been seeking devs / interest in Signal for our Librem 5 (in the PureOS environment, not Ubuntu Touch). Had a few conversations with OWS/Moxie as well.
I knew about this app but development seemed stalled... but it looks like it has a shot in the arm now 
Can we chat about ways that we may be able to support you to get this running in PureOS on the Librem 5? Drop me a line sean.obrien@puri.sm if so.