The best replacement for airfoil is airserver.

The best alternatives to airfoil are rated as following:
★★★★★  airserver
★★★★★  wing
★★★★  porthole
★★★★  airparrot
★★★  aerofoil
★★  wifi2hifi
★★  tuneblade
★  airtunes
★  pandorajam
★  hydrofoil
  flat wing
  flat plate
  jamcast

Your alternative for airfoil is not listed? Suggest!
Speaking about airfoil, one probably shouldn't forget about airport express.

Other search terms related to airfoil and their ratings are:
★★★★★ airport express
You have in mind a companion for airfoil and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of airfoil in all years. Click on graph for more.
airfoil
airserver
wing