免费版到付费版方案:

了解为什么您只应在免费的应用内进行付费 版本

To understand why you should only go for in app billing inside free version

1) 免费升级到付费Android应用程序而无需留下两个图标

2) 是否可以用付费版本替换现有的Android免费应用

两种情况:

3) 在应用结算实施中，从免费版本购买付费应用

3) In app-billing implementation , buying paid app from free version

毕竟，您可以选择要开发应用程序的方式，但要根据我的建议:

After all it is your choice to select the way as you want to develop app but according to what I suggest:

您应该选择仅在免费应用程序版本中提供所有功能，然后在应用程序流程中添加简单产品后升级功能.

you should go for the first option that you should provide all feature in the free app version only and upgrade your feature after simple product in app flow.

希望您为应用程序中的进一步开发流程扫清了障碍.

Hope you clear the way for the further development flow in your app.