I think it would be really helpful to have a filtering option under NRST to select nearby ATC frequencies. This would be either the appropriate TRACON frequency, where such exists, or the ARTCC frequency. For pilots who need to pick up an IFR clearance enroute, or just to VFR flight following, this would be exremely helpful. It would also be good to include the locally overhead ATC frequency for more airports in the airport information box, even if that facility does not provide approach services.
The NRST filtering option is available in a number of competitive products.
Andy Elliott , v10.3.52 on Huawei Mediapad M3 8.4, Android 7.x, uAvionics ADS-B