function appTask()
  local app-list = {}
  while true do
    local evt = {os.pullEventRaw}
    if evt[1] == "openApp" then
      local co = {co=coroutine.create(appEngine.launch)}
      co.trg = coroutine.resume(co.co,evt[2])
      app-list[#app-list+1] = co
    else
      local co = app-list[#app-list]
      if co.trg == nil or co.trg == evt[1] or evt[1] == "terminate" then
        co.trg = coroutine.resume(co.co)
      end
    end
    if coroutine.status(app-list[#app-list].co) == "dead" then
      app-list[#app-list] = nil
    end
  end
end