Signals Blog

Product Preview: ChemWriter App for iPad

Note: the ChemWriter iPad app has been discontinued. ChemWriter 3 continues to be available.

Within three short years, tablet computers have gone from clumsy gadgets few cared about or bought to workhorses rapidly replacing laptops and desktops. Key to this transformation has been a booming app economy. Although many software categories such as entertainment, business, and time management have been inundated with new apps, niche ares such as chemistry research and advanced education have experienced a more muted uptake.

Chemical structure editors are essential tools in modern organic chemistry and related fields. This article offers a preview of a new chemical structure editor app for iPad® devices now under development at Metamolecular.

About ChemWriter

ChemWriter® is a chemical structure editor originally built for use on Web pages. As such, it's a tool for software developers. ChemWriter isn't currently something that most chemists would have a need to buy for themselves. However, given numerous questions I've fielded on this very topic, the demand for alternatives in this space is quite clear.

Over the last five years, ChemWriter has evolved significantly, mostly driven by excellent customer feedback. A lot has been learned about what works and what doesn't for browser-based chemical structure editors.

Now it's time to apply that experience to building a great chemical structure editor app for iPad devices.

Fast and Fluid

Users of tablet computers expect a different experience than users of desktops, and it's important to deliver on those expectations. Although tablet computing resources like memory and processor power are quite constrained compared to desktops, it's critical that these limitations never show themselves. From the first moment an app is launched, every user interaction with it needs to be fast, fluid, and intuitive.

For this reason, the ChemWriter app is being written from scratch around the touch screen. Details of the development process may be the subject of future posts. Suffice it to say that the ChemWriter app is being written with a keen respect for the iPad's strengths and limitations.

Features and Pricing

A two-tiered pricing model is currently envisioned in which basic drawing functionality would be available in a free app. An in-app purchase would then enable premium features.

Free Features

Premium Features

Initial releases would focus on enabling the fast and efficient drawing of chemical structures through a touch interface. A major problem to be addressed is how to enable precision structure drawing using a non-precision implement (the finger).

Also available in the first release would be the ability to read and write files in a variety of formats. Chemistry formats including molfiles and ChemDraw® files would both be supported, as would image formats including SVG and PNG. The app would support seamlessly moving these file representations into and out of popular cloud-based storage utilities including iCloud® and DropBox®.

Subsequent released would focus on calculations and derivation of other kinds of information from chemical structures.


Tools for drawing and using chemical structures are essential in organic chemistry and related fields. A new app based on ChemWriter is in development that aims to bring high-quality structure drawing and analysis to iPad devices.