No problem. I use unity3d, its actually a game engine however its very powerful in that it lets me to compile both for Android and IOS from the same build. And it lets me work in C#.
Its also free.
The frontend for BLE I use however is not free and it requiers one license per developer. But its only 17$ and for the price of 2 pizzas the amount of work put into it, its well worth it.
Those who want access to the source must show that they own the license (Link below).
Releasing to IOS is also a pain since you would need a developer account on app store, i Think it was something in the line of 90$ per year (Android master race)
If anyone does have a developer account i could send over an Xcode Project ready for compilation.
Releasing betas for ios thru TestFlight is free but if i remember correctly they need to pass a review and its not exactly turnkey release för the receptient.
Bluetooth LE frontend: https://assetstore.unity.com/packages/tools/network/bluetooth-le-for-ios-tvos-and-android-26661
Android SDk: https://developer.android.com
Java JDK: http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html