If you are reading this, then more than likely I have just sent you here after you have emailed me for some support. Now, I hope you don't think I am being rude or lazy, but sometimes I am just not in a position to help with your request - it's not that I don't want to help you, it's just that in this situation, I can't.
More often than not, the reason I can't help you is because you have asked about something to do with the actual purchasing and downloading of one of my applications from one of the various app stores they are available from. So you could be having trouble completing the order, or maybe you are getting an error from the app store when you try and download, or perhaps you are being told the app store can't verify your purchase. The fact is that I am an independent developer and so can only support my own applications; I don't work for any of the app stores and so I don't know how any of those systems work from a users point of view. Therefore, I can't offer support for them and can only suggest to you to contact the support team for that particular app store.
There is one small exception in that for the Google Play Store, if you provide me with an order number, I can actually see the status of your order (and refund it if necessary). So if you'd like me to do that then I am more than happy to; just email me with the order number and I'll see if I can help you out. But also remember that you can see the information you need yourself simply by logging into your Google Wallet account online and looking at your transaction history. I am afraid I can't offer the same service for any of the other app stores because I just don't have access to that information on an individual order basis.
Another typical reason you may have ended up here is that you are asking questions relating to the general operation of a particular device. I only have a handful of Android devices myself, so although I may be able to answer a few questions, you are far better off contacting the manufacturer's support team for that particular device.
So sorry I can't be of more help to you in this situation, but hopefully this has prompted you to contact the support team that can resolve your issue in the quickest way possible. Of course, you may still think I can help you, so please don't hesitate to contact me again and I'll see what I can do. But just remember, I can only support my own applications... I may occasionally be able to help beyond that in some situations where my applications are a factor, but you are most likely reading this blog post because I already think I am not best person to contact for your issue.