BTW the VHF/UHF and maybe lower band RX software defined radio is probably not a quick cut/paste option for the established GTA04 though it could be connected with only a few GPIOs later in a new phone/tablet case.
Just for info a software defined radio modulates the signal from a software controlled modulator so any radio modulation ie: AM/FM/SSB/FSK/CW modes are possible on any frequency the tuner can achieve.
Since we already have several microwave band black box radios in our phones already it would be possible with the correct protocol software stack to say emulate GSM, wifi, bluetooth, nfc, xbee, umts, etc; even some satellite up/downlink data protocols and HDTV from a software controlled radio, best part is the whole system would be fully open as the modulation would be accomplished with software written on OSS by our community.
Even if the UHF/VHF radio were not a SDR but only software tuning controlled and modulation fed from pulsaudio in FM mode it would/might allow it to RX/TX:

-FRS/PMR446/GMRS/MURS unlicensed/public walkie-talkie mode
-Marine VHF band
-Old VHF and UHF public safety band(for volunteer firefighters and police reserve)
-Air band(distorted, possibly shortened range)
-Amateur(ham) radio simplex, repeater, and satellite(with ext antenna) services
-APRS position and telemetry reporting over amateur and unlicensed bands between phones and APRS equipped radios
-UHF low bandwidth commercial satellite data communication modes
National regulation agencies might require the UHF/VHF chip to be disabled in software and a quiet unofficial community 'hack' to enable or hackable filters to initially restrict the radio to local unlicensed or amateur radio bands.

An additional AM shortwave-medium wave receiver again like the Earl Android tablet and external antenna(3.5mm audio jack?) would permit receiving shortwave signals worldwide including news, music, and some amateur radio transmissions, more options if the AM rx had a simple carrier wave injection to the mixer so power efficient amateur radio and pirate single-sideband signals can be decoded.

All of the above would be great once we move beyond the GTA04-Neo900 stage to a next gen phone and/or tablet.