Ady, much more than that! Santa brought me a smartphone, just so I can play with 'apps', as I have a steam-powered phone to make calls and texts on when out & about. The amateur radio ones are mostly formulae, aerial sizes and propagation workings, and the science ones are the periodic table, chemical formulae and home experiments. The ones I am having most fun with are Night Sky Pro, far better than 'Redshift' on the PC, and FlightRadar 24, monitoring aircraft in real time, superimposed on Google Maps, so that, for instance, I can pick up an aircraft, flying North over the Peak District, and watch its progress over the satellite picture of the ground below, as it prepares to land at Manchester, having described a graceful U-turn over North Manchester, constantly updated from the aircraft's own transponder, all the way down to landing. Below about 300 feet the accuracy deteriorates, sometimes it seems to fly backwards, or appears still in the air, having landed (0 feet, 0 mph) but it is great to watch.
Having played with (sorry, studied) it for some months, I have collected several practical apps like, Stroboscope, Plumb-bob or the very similar 3-axis Gravitometer, Magnifier, Audio spectrum analyser, sound level meter, frequency meter, oscilloscope, tone generator, pedometer, etc. I have tried two radioactivity detectors, without success, unless my basement is a very benign environment. The Vibrometer is very sensitive, detecting passing traffic and the desktop computer fan. Google something like 'Free Android stroboscope app' as required and try one. Many are free or only a nominal price, and the choice is growing all the time.
Geoff