
How We Built an iOS App, an Android App and a Node.js API in 20 Hours - govind201
http://blog.semantics3.com/how-we-built-an-ios-app-an-android-app-and-a-node-js-api-in-20-hours/
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chris_dcosta
I congratulate them on acheiving your goal of writing an app in such a short
time, but I whole-heartedly condemn this app's principle idea. Far from being
a force for good it feeds into the incredible paranoia that seems to be
prevail in the United States, that everyone is out to get them, and that there
are such things as "good areas" and "bad areas".

There are huge problems in justifying this kind of classification, not least
because ordinary law abiding citizens who are in a majority also live and work
and play in so-called "bad areas" and never suffer crime. What becomes of
their house values if such an irresponsible app were to become popular? Their
(very) hard earned cash paid as mortgage payments gone to waste.

This app is pernicious in every sense. Even wealthy well-to-do areas can
become ghetto-ized: If you tally up the number of burglaries or attempted
burglaries in these areas you might find the stats show a different image.

We are not living in some post-apolcolyptic movie world, this is real life and
has hard working real people in it, with families and children, who have no
choice but to live where they can afford to, and I don't see how this app
could ever be considered as "making the world a better place". For who
exactly?

This kind of app threatens to push people who live in the targeted areas
further down the food chain, and I just wish the developers would have been a
bit more socially responsible, in their thought processes.

Rant over. Hopefully a lesson learnt.

~~~
govind201
The app was born out of personal experience. Within a month of moving to
Philadelphia, I was assaulted on two occasions, including once on my very
first day there. I put that down to my lack of knowledge of the area; I later
discovered that a more knowledgable person wouldn't have accidentally wandered
off at that time of evening to that particular area. Turns out, some of my
neighbors had had similar experiences in the past in the very same area. I was
later warned by local authorities that the area was known for the phenomenon
of "gentrification".

Personally, I was scared out of my wits after those two incidents and landed
up staying home many evenings for fear of a repeat incident. I think such an
app could've really helped the general quality of my life in terms of reducing
my apprehension.

I do see your point. To be honest, I didn't give the macroscopic windfalls
excessive consideration. I had focused rather on the gains to individuals who
stand to face the same situations that I did.

The app has not been released publicly so I think I'll do read a bit about
crime patterns and their correlation to demography before taking any further
step. Thanks for brining this to attention.

~~~
rwhitman
Having been raised in the Philly area I've heard this story from non-natives a
number of times, so its pretty common.

That said I think the flaw in this from a positioning perspective is it
shouldn't be an alarm that says "Danger, get out now!!!" like you're in a
biohazard zone, its should be positioned more like a "Street Sense" radar.

Basically you learned urban street smarts in the hardest way possible. Make
this more about softening the risks of navigating unfamiliar urban areas by
giving folks the same level of street smarts as a native, and less about a
shock and fear-based motivator and you'll be on the right track.

I would also consider focusing on safety by highlighting safer routes pointing
out things like density of businesses and street lighting, police stations
etc.

~~~
chris_dcosta
Totally agree. This is a much better approach.

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Czarnian
The feat of building that kind of app is impressive. I sure as heck can't do
it, yet. I do have a few comments, though.

Refine your data classification. On one of your screenshots, you are listing
"Arrests" as a type of crime. That's confusing. Also, consider filtering for
violent crime rather than crime in general. That would be more in line with
the stated purpose of your app.

Realign the usage from a real-time application to a planning application. You
don't want your users to be fiddling with a smartphone in a bad neighborhood.
That really increases the odds of getting mugged and defeating the purpose of
the app.

I agree with some of the other posters that you should tone down the alarmist
tone of the app. If nothing else, it's more professional.

Congratulations on your experiment.

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caw
What's the time function on your graph? Are you only showing the last X weeks
or all time? Things like police patrols could affect the frequency of crime
over time, and that may change your predictions and confidence intervals.

EDIT: Depending on your data freshness, you may want to do something like push
notifications if a crime happened in your area in the past 4 hours. That way
if someone walks through a "good area" but there's recent crime they should be
more vigilant.

~~~
vinothgopi
We managed to gather data for about a month when building this app. Some of
them were as recent as a few hours and some a few days.

We implemented a weighted average algorithm to calculate the risk levels and
how confident we were of the data. For the risk levels I took into account 1)
How recent the data was 2) What time of the day it occurred relative to the
time of query (for eg: the crime occurred at 4pm on another day and its 5pm
now, it will be given a higher weightage compared to something that happened
at say, 11am.) 3) The severity of the crime itself (murders >> theft) 4)
Number of occurrences of crimes in the area

The assignment of weights wasn't thoroughly scientific though. It needs some
tweaking.

And thanks for the suggestion on push notifications :)

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donpark
I had similar idea whileback so this app is interesting.

What I would change:

1\. Remove crime details. They are unnecessary. 2\. Replace pins with
transparent canvas overlay showing level of danger or safety in shades of red
and green. 3\. Let user set the desired 'shade of danger'. A simple horizontal
or vertical color selector showing shades of red will do. App should buzz
every N minutes when users is in area with deeper shade of red unless they
press the override button.

That's all.

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varelse
Tip of the hat: you beat me to the punch (though I really wondered about the
proper lawyerese for deploying a service like this)...

Of course, the corresponding app, badguy, which alerts would-be criminals to
the likely patrol routes of cops, is likely to follow shortly thereafter from
the black hats.

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rdg
Great, give clueless "project managers" another reason to think anything of
value can really be accomplished in a day or two.

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crazygringo
Is this available on the App Store yet? Or is there an estimated date?

~~~
vinothgopi
The designer of the iOS app is sadly a perfectionist and is refusing to put it
up on the store until its pixel perfect!!(by his own standards)

In all seriousness, we have a bit of work validating the ranking algorithm,
pulling in more sources and general UI cleanup stuff. We are really keen on
putting it on the store though. Maybe a couple of weeks to a month?

~~~
crikli
I travel a fair amount for business and have contacts that also travel quite a
bit. Let me know if you'd like some beta testers once you get beyond the
California area.

