Want to list a couple of apps here that I use often. I use an Andriod so not sure on the apps available for iOS.
1) Virtual Tycoon - This one allows you to log in when you are not logged into the PC client to check your inventory, skills, and most important those items you are trying to score on the Auction House (AH).
2) Entropia Information - This allows you to do searches for most all things in Entropia. Gives you the ability to search for most all things in the game. You must update the database after installing.
3) Entropia Toolkit - This one has a few calculators in it but has a nice Location Save feature.