The cameras on the iPad are both less than 1 megapixel and as you've noticed do not take great photos, I'm not sure of any apps which can enhance them and I will also be interested if other members are able to suggest an app.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.