Yapp rhymes with:
yap, app, cap, capp, chap, chapp, clap, clapp, crap, dapp, entrap, flap, frap, gap, gapp, giap, hap, happ, happe, jap, kapp, klapp, knapp, krapp, lap, lapp, lappe, map, mapp, nap, napp, pap, papp, rap, rapp, rappe, sap, sapp, schapp, schnapp, scrap, shap, shapp, slap, snap, snapp, stapp, strap, tap, tapp, tappe, trap, trapp, trappe, unwrap, wrap, yap, zap, zapp
Yapp sounds like:
yabba, yaffe, yap, yep, yip, yippee, yoffie, yopp, you've, yuba, yup, yuppie, yuppify