Android app for NeighbourBlog.com - repost

We are looking to do a mobile app for our website NeighbourBlog.com. Currently we have a hybrid app in Google Play using Rest API to push and pull data,however it is very slow and freezes as well. So we would like to do the same functionality in a native Android app without changing our back end WCF rest API. .Please note we are very small company so we are not looking to spend a lot of money on this. If interested, please get in touch with your rates and how long approximately it would take to finish the project. Please also include relevant examples of your previous apps ,if you have any. NO AGENCIES,PLEASE.