Why don't people just use a stateless VPN like SigmaVPN[0]? Also, since android is linux, why not use one of the many bonding options?
I'm using it to bond two 4G interfaces (Verizon + Clearwire) on the train at this very moment. Need to remember to bring a USB wifi adapter next time so I can add the Amtrak wifi to the mix!
edit: No linux support though. :/
Maybe tinc-vpn would be an option though.
No bonding on Android, since there's No App For That (at least I know of none?). Doing that in a terminal, on a phone, is really the last thing I'd like to play with.
Or did I misunderstand your second suggestion?
Bonding wouldn't require SigmaVPN, just the regular Linux tooling and driver/kernel support.
[0] https://play.google.com/store/apps/details?id=com.frozenrive...