android app developement suggestions required

guide me with proof and logic so the work could be awarded to you. only serious, real and relevant persons post their comments so i can consider to work with them read all the details carefully so you can better comment and get the project. a friend/client made this android file manager app whose link is given below; [login to view URL] currently this app is facing issues of a large number of ANRs and Crashes , due to which the owner of it is getting almost same number of app uninstalls as compared to app installs. what should we do other than ANRs & Crashes to add features in it, so the user like it? what features should be added in this android file manager application? at one point he think to get this app created totally new on Xamarin platform for android devices, is this a right decision?