Musicians who’ve had some degree of practice will know the lack of sophistication involved in getting an instrument in tune and on time: a light-up tuning box and a swinging metronome may be their only real resources. Affinity Blue knows that mobile apps allow better, and recently unveiled Tunable as a one-stop shop for more exacting performers. The Android and iOS release provides a live graph that shows where the sweet spot is for pitch, and how closely the music has followed along for the past few seconds — a boon for brass players, vocalists and others who need to sustain a note for more than a moment. There’s also a simple tone generator and a customizable metronome that’s easily seen from a distance. While it’s $1 to try Tunable, that might be a pittance for anyone who’d rather spend time mastering a riff than rehashing the basics.