I bought a WINGStand for the iPhone. It clips onto an Apple bluetooth keyboard and holds the iPhone (or other mobile device,) making it easy to type up a long document when you don't have access to your iPad or MacBook.
It fits the iPhone with a shell case perfectly, but the case I have is probably the biggest that would fit. According to the website, it can accommodate cases that are 0.5" thick. I think the 0.5" references total thickness of the phone and case, however.
There are two plastic pieces that snap together when not in use. The plastic feels pretty sturdy, and they clip to the Apple keyboard firmly. The website doesn't specify, but I'm pretty sure it will only attach to the Apple bluetooth keyboard. You could, however, use it as a simple stand if your device is paired to a different bluetooth keyboard.
Now I have options for writing. Laptop, iPad, and iPhone. All on a normal-sized keyboard. Typing full blog posts on the iPhone will be much less painful on my thumbs.