Bethesda, Md. - Kajeet, the provider of mobile services for "tweens," announced on Wednesday the launch of its service -- a pay-as-you-go wireless service aimed at children between the ages of 8 and 14. The company said the service -- which operates on the Sprint Nextel network -- has begun rolling out, and will be available nationwide in Best Buy stores by May 1, and at Limited Too stores in early April. The company last year announced that it had raised $27 million from Bessemer Venture Partners, Gabriel Venture Partners, InterWest Partners, and FidelityVentures.