NG doesn't care, it's closed down anyway, and downloading costs money. Maps and Google Maps have a lot of traffic, so it is better to install R66, which is also very powerful. The expiration of the signature is simple. When you can't install the software, move the phone time forward for a few years. If you are interested in cracking, use helloOX to crack (recommended). If you want to sign a contract, apply for Saipan Forum. Don't bother, this is a smart phone, similar to a computer. I recommend several softwares. The following softwares are definitely the best of their kind (I picked and picked), such as Xinyi, sogou, UC, Xplore, Navigation Desktop, LCG, smartmovie and jbaktask. Mine is also N79, which I learned from Saipan Forum. You'd better go and study.