I'm on App v3.0.17 and it seems to work fine with V4 (except the Stunnel thing) and it no longer warns about upgrading to 5 (which IIRC just said some app features may not work, not that it required V5).
Android app ver 3.0.14 = Can't reach server over https but http is OK. Can run BI3 in browser over https from said phone. Still running 4.8.6.3 on PC. Sombody suggested new android app might not support 4 but hopefully somebody will confirm.
My old post was deleted cuz I linked to a post in a...