Creating the “Blood Pressure Chart” App: An Independent Developer’s Story

by Mateusz Mucha. Mateusz is a freelance web application developer from Krakow, Poland.  31 y.o., married, enjoys rock climbing, sailing, skiing and having 6 meals a day. Contact him at muszek@gmail.com

This is a short story about Blood Pressure Chart – a web-based tool used to manage, analyze and share blood pressure records. The old saying, “necessity is a mother of invention”, is almost applicable here. Almost, because coming up with an idea to store whatever records in a web app is hardly inventive. Certainly not in 2010. Strangely, a moderate set of requirements could not be satisfied by any preexisting solution.

For at least the past decade, I’ve been hearing about my country’s health care going digital. Millions (billions?) of taxpayers’ dollars later, I was given a paper notepad to record my blood pressure.

Having seen a doctor using a typewriter recently, I wasn’t really surprised, but simply had to find a better way. Few hours of googling and checking out a few desktop apps and one web app made me realize that nobody has taken it seriously so far. “I could make something much better in a week”, I thought to myself… but ideas for new functionality kept on coming and around a month later the site was ready.

When you create pretty much anything, it’s good to start by asking yourself a few questions before you touch any tools. Who is going to use it? What do they want to use it for? What are strengths and weaknesses of competing solutions? What non-standard functionality can we offer to enhance user experience?

First and foremost, I’m competing with a simple paper notebook.

While it’s far from being a powerful tool, it has really important strengths: it’s easy and fast to use. And these qualities are going to be to base of comparison against any solution that aspires to be a replacement. People won’t be willing to spend any time learning the interface or using the tool every time they visit. What do they use it for? While there’s a lot of things the app could do for them, it primarily needs to let them add records.

This very basic feature must be implemented well and kept in mind whenever new features are building up. It has to be as convenient and as easy to use as a paper notebook. It’s not really rocket science – we need to make it quickly and easily accessible (the add button is the first one in the main navigation menu), sufficiently described (hovering over any element brings a tooltip) and plain (everything beyond the basic functionality is hidden).

Having made sure we’re not going to scare away newcomers, we can proceed to the fun stuff. So how can we actually make use of the tools at our disposal to provide a valuable service to our users?

• Visualization – a picture is worth a thousand words, right? Looking at my own chart, it’s easy to see how my systolic pressure dropped after I started taking new meds around July 9, 2010 (scroll or expand the time frame).
• Analysis – that’s why records are kept in the first place. Use either the aforementioned chart, the table for a fine-grained perspective or look at statistics to see the bigger picture.
• Sharing. After all, records are kept for the doctor. Printing, while useful is… well… going back to paper. You need to have the printout with you, it’s far less flexible and not very eco-friendly. I’ve implemented two different modes – you can make all your data public and give others the address to your chart, table or stats (just as I gave you links to my data above). Of course, you can turn this feature off and send your data by e-mail.
• Reminders. Simple thing – I keep forgetting about everything. It’s important to check BP regularly, preferably at the same times of day. Users can create e-mail notifications set for a specific time, either everyday or on a specific day of week.

There’s quite a bit more smallish features and a lot of ideas submitted by users, some of which are waiting to be implemented. Having designed everything with a KISS principle in mind, it’s sometimes hard to explain that feature X, while useful for a fraction of users, will just clutter the interface for all others.

Blood Pressure Chart started out as a simple hobby, non-commercial project and I treat it this way. A still small group of users seems to like it a lot (I’ve got quite a bit of “thanks” emails). While it’s fun to develop and makes me happy that the site helps people, I’m aware of the fact that it’s just not one of those things that will promote themselves and it won’t go beyond a few hundreds active users. It’s been 4 months since the site went live and I start to wonder – what’s next?