What are the best iTunes apps?

What if your apps that you have already downloaded onto itunes won't sync (apply) on to your ipod?how?what?

• What do i do?who do i ask i downloaded these apps but they just won't for some crazy reason apply on to my ipod): and it would be nice if someone could explain why they dissappaer and why they won't go on my ipod.so.................... What do i do to get my apps onto my ipod? Please answer.Thank You(: * (:

• Answer:

  Go to your apps, click and drag the app(s) to the "my iPod" section and watch it sync! Same with songs, videos, etc