RadioShack on Tuesday announced the upcoming exclusive availability of Sprint’s flagship HTC EVO 3D smartphone in white. The handset will become available on September 9th, and it will be priced in line with the standard EVO 3D at $199.99. Sprint’s premier Android smartphone has been a big seller for the nation’s No. 3 carrier. The EVO 3D features a 4.3-inch qHD 3D display, a dual-core 1.2GHz Snapdragon processor, Android 2.3 Gingerbread and dual cameras for recording 3D content, and we said it was our favorite Sprint phone, hands down when we reviewed it in mid-June.