Site Survey portable IOS Antenna, IOS App In/ON building site

Not vehicle attached drive around Site Survey style equipment but specific Intra building/roof top surveys using IOS Cell Phone App fed by a portable Tower Antenna. There is a huge SMB/SOHO & mid-size Enterprise market that requires mapping out and tweaking tower signals intra (inside) various building structures or rooftops.
Does anyone know of such a portable carry about cell phone app or an portable antenna & laptop Windows/Linux version that can provide continuously updating (T-Mobile, Version, AT&T) tower signal metrics?
If necessary this solution could integrate a BR1/2 MAX PRO.