Recently we have updated both TeX Writer and TeX Equation. Now they share a same compilation core. This will make our future update much easier. For TeX Writer, we add a spell checker. You can enable it from TeX Writer settings by selecting a spell dictionary. Instead of putting all dictionaries in the app, we have a list of dictionaries on the cloud so you can pick the ones you need and install in your device. In this way, we can keep the app package as small as possible. The philosophy behind is that the users should not be forced to download anything he/she doesn't need. The TeX editor inside TeX Writer also highlights formulas between a pair of $, such as $x_1$. By default it is shown in red, but you can use the following command in twinit.l to redefine:

(set-string-color <red> <green> <blue> 1)

red/green/blue are numbers in range 0 to 1.0. TeX Equation now offers three ways to get the equation images out:

1. Copy as PDF. Most recommended way. Keeps high resolution.
2. Copy as PNG. Retina resolution, transparent background.
3. Export to album as JPEG. Retina resolution, no transparency. Too bad iOS doesn't offer a way to save PNG to album.