What is the best book or resource for mobile development with Unity?

I am in the process of starting on a mobile game. I am an intermediate Unity artist-developer but have not done for mobile. Is there any great resource book or resource that is current and that can help with a bunch of challenges I might face going into mobile.

Much appreciated.

 

For intermediate artist-developer, I think you just need some advices, tips& trick..
1. Multiresolution - you got what it means, the game should scale up&down for different resolutions. I use xArm asset and it does really help a lot... You should check everything, gui, game, and etc.. It must nicely fit on all devices. xArm is the asset which will help you.
2. Reduce draw calls, use low poly models, atlas the textures. For new mobile phones, the texture size of 2k is ok, though newer ones might support more, Im not aware. But if you want to be sure that even the older phones will be able to play your game, then texture size should be 1k. Also, the texture must be power of 2.( 128x128,256x256, etc)
3. Use mobile shaders. There are a Core Framework asset, which has heavly optimised shaders for mobile. I didn't use it so far, but it's on my purchase list and it has amazing feedbacks..
4. The battery life - it's one of the important parts. If users will see that your game kills their battery, then you will probably have less installs and negative reviews.

You can also check the amazon.com, for Unity3d+mobile combinations, but there are not that many books about mobile dev and optimisations. The above 4 aspects which I've mentioned are easily googlable, and you can find more informations by simply googling.

 

Thank you for the info! really appreciated.