Warp cuts the dead air out of talk and then tells you how many hours it has given back, which is a more satisfying number than any listening streak. Signal Boost is a real-time EQ aimed at the specific problem of one loud host and one whispering guest. The whole app is 10.7 MB, needs no account, and keeps what you play on the device; Pro adds transcripts and unlimited downloads for $14.99 a year.