Ultimate++ is "ok", but they don't do iOS yet + I in person think their C++ usage is weird - unreadable.
http://www.ultimatepp.org/www$uppweb$apps$en-us.html
They have very good graphics support and fast compilation technique.
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Other than that I would consider QtCreator for GUI as they support both Android and iOS. They learning curve is a bit harder than Lazarus, but it is a far more powerfully platforms once you get going. The last release included code from 400+/- developers and 100+/- of those are full time so this is heavily developed. It is free (LGPL), you can buy commercial license if needed and I even see jobs advertised for Qt.
Myself I use Code::Blocks and CooCox. I also use Visual Studio which is superior as IDE, but their C++/MFC is not what it once was (fallen behind). I am not doing GUI in C++ anymore, otherwise I would be using QtCreator.
For iOS I would consider XCode and Objective-C.