Oh, the irony. The Hangouts app for Android got a whole lot better recently when it integrated the Google Voice service into itself — mostly good news except for old, slow Android devices which can no longer bear the burden of this now-bloated software. So I set out to find an alternative, specifically for my old Sony Ericsson X10 Mini E10i, so I can at least send and receive Hangouts/Google Talk messages on it.
Simple XMPP Client has a very small footprint (622KB), which I liked, but the features are too limited. You cannot even have it auto start. Plus it does not support multiple accounts.
yaxim – XMPP/Jabber client also has a relatively small footprint (1.2MB) and also does not support multiple accounts, but at least it auto starts as the device is turned on. Incoming messages are not shown in the notification area, which is a little inconvenient, but is still usable. Okay, I will use this one for now.
Xabber is definitely rich in features but heavy (2.5MB) also. It supports multiple accounts so if I should one day feel like being constantly annoyed by messages on Facebook Chat too (yeah, right), I might switch to this one.