Personally, I use Google Earth, Google Maps, and Baidu.com to plan my hiking routes. It's not comparable to our famous French IGN maps, but I haven't found anything better.
In France, I use Maps.me on my phone, but in China...
Following the latest "movement" in this discussion thread yesterday, I just took a look at 高德地图 (Gaode Ditu), which I'd heard great things about years ago.
I tested two routes that are "dear" to me:
On the computer version, it looks very clear.
For example, to get to the magnificent Gaopai festival in late December 2007 (9 nights on site), I had to get off the bus at 兴华 Xinghua, then leave the road (Gaopai was far from any roads back then) for a 3-hour walk (in theory, because I ended up taking 9 hours due to "wandering" and arrived in the middle of the night. The women in the fields didn’t understand Chinese. There was no path). On the way back, I followed locals who knew how to walk along the edges of the terraced rice fields without any signs (I think this type of route isn’t accounted for in this software).
Xinghua-Gaopai route: 3h 15, 1km
http://gaode.com/dir?from%5Badcode%5D=522632&from%5Bname%5D=%E5%85%B4%E5%8D%8E%E6%B0%B4%E6%97%8F%E4%B9%A1&from%5Bid%5D=B03570N5AC&from%5Bpoitype%5D=190106&from%5Blnglat%5D=108.16245700000002%2C25.831805&from%5Bmodxy%5D=&to%5Bname%5D=%E9%AB%98%E6%8E%92%E6%9D%91&to%5Blnglat%5D=108.182244%2C25.904095&to%5Bid%5D=B0357000TY&to%5Bpoitype%5D=190108&to%5Badcode%5D=522600&to%5Bmodxy%5D=108.182244%2C25.904095&type=walk&policy=0&dateTime=nowThree years ago, I was in 脚车 Jiaoche, a pretty "well-preserved" village that, I was told, isn’t so "preserved" anymore.
I knew there was a path leading to nearby Gaopai (for pedestrians but not accessible to vehicles). Here it is:
Jiaoche-Gaopai route: 1h10, 5.9 km
http://gaode.com/dir?from%5Bid%5D=B0357001AO&from%5Bname%5D=%E8%84%9A%E8%BD%A6%E6%9D%91&from%5Blnglat%5D=108.204894%2C25.929347&from%5Bmodxy%5D=108.204894%2C25.929347&from%5Bpoitype%5D=190108&from%5Badcode%5D=522632&to%5Bname%5D=%E9%AB%98%E6%8E%92%E6%9D%91&to%5Blnglat%5D=108.182244%2C25.904095&to%5Bid%5D=B0357000TY-to&to%5Bpoitype%5D=190108&to%5Badcode%5D=522600&to%5Bmodxy%5D=108.182244%2C25.904095&type=walk&policy=0&dateTime=nowWell done, Gaode. I haven’t found any paths more clearly marked in China’s mountains.
On the other hand, it must be much less practical on the phone version (small screen, limited battery life, and how to use Perakun or similar for characters you don’t know?).
I’ll check it out during my next trip to Qiandongnan when I go pick up my new passport, which is ready.