Getting someone to download your app is hard enough. Don't scare them away with constant crashes, bad behaviors and errors which make your app unusable. During my presentation, I'll go over techniques, habits and tools to keep your iOS app in tip top shape.

1. © 2017 MOBDESIGN
Don’t lose your users because of
Endless Quality Issues
Olivier Destrebecq
@otusweb
olivier@mobdesignapps.fr
http://www.mobdesignapps.fr

2. @otusweb
Users are expensive
SUBSCRIPTION APPS COST &
CONVERSION FUNNEL
GAMING APPS COST &
CONVERSION FUNNEL
SHOPPING APPS COST &
CONVERSION FUNNEL
Source: liftoff.io User Acquisition Trends and Benchmarks SUBSCRIPTION APPS REPORT 2017
Install $4.40
Register $30.51
Subscription $161.38
Install $4.07
Register $8.94
Purchase $50.69
Install $4.45
Register $30.51
Purchase $75.86
14.43%
Install-to-Register
2.73%
Install-to-Subscription
45.5%
Install-to-Register
8.0%
Install-to-Subscription
14.6%
Install-to-Register
5.9%
Install-to-Subscription

3. @otusweb
Crashes are expensive
Imagine an app with
2 Million MAU
Stable at 99.7%, so only
0.3% of users see a crash
60 000
users a month will see a crash
Only 16% of user will try a failing app more
than twice. If 10% decide they are done
because of the bug, that is
6 000 users
$24 000 at $4 install
Does not even take into account the cost
to convert that user to being a client
Source: TechCrunch citing Compuware study

4. @otusweb
So how do you avoid this?
All slides available on Twitter (with extra links)
@otusweb #mobilization2017

5. @otusweb
Get started right
Know which scenarios you want to enable AND STICK TO THOSE!
Take the time to iterate on design: Issues in design are easy and cheap to fix
Set up your team correctly, know where the buck stops
Work with people you enjoy working with
As a team pick your approach to keep quality up

6. @otusweb
Perform user testing
Get users from your target segment and show them your early prototypes
3. Observe and shut up
4. Answer questions with questions
Bad: “Did you easily find the search
button?”
Good: “Which information is most
important to you?”
1. DON’T LEAD THE WITNESS 2. ASK USER TO GO THROUGH YOUR MAIN SCENARIOS
Bad: Go to shirt section and pick a
shirt
Good: You want to buy a new shirt for
work. please use this app to find one

7. @otusweb
Security: a fine line, walk it regularly
Don’t be an Equifax, Target or Yahoo
Use the OWASP Mobile App Security checklist
Prioritise and mitigate
Review it regularly

8. @otusweb
Version control is your best friend
Pick one, learn to use it and use it
Ease collaboration
Understand what happened
Reverse time
Use a branching model
Multiple release going on at the same time
Main development does not halt for release
Feature
Branches
Develop Release
Branches
Hotfixes Master
Time
Tag 0.2
Feature for
future
release
From this position
on, “next release”
means the release
after 1.0
Major feature
for next
release
Incorporate
bugfix in
develop
Severe bug
fixed for
production:
hotfix 0.2
Tag 0.1
Tag 1.0
Bug fixes from
rel. branch may
be continuously
merged back
into develop
Only bug
fixes!
Start of
release
branch for
1.0
Source: Vincent Driessen : A successful branching model

9. @otusweb
Bug life cycle
Defines bugs states and
responsabilities
No bugs falls through the cracks
No bug fix gets released without
testing
Developer cannot close a bug
New bug from a user
with con confirm or a
product without
UNCONFIRMED state
Bug is reopened, was
never confirmedBug confirmed of
received enough votes
Developer takes
possession
Development is
finished with bug
Developer takes
possession
Ownership
is changed
Development is
finished with bug
Developer takes
possession
Issue is
resolved
Bug is
closed
QA not satisfied
with solution
QA verifies
solution worked
Bug is reopened
Bug is reopened
Bug is closed
UNCONFIRMED
NEW
REOPEN
CLOSED
RESOLVED
Possible resolutions:
FIXED
DUPLICATE
WONTFIX
WORKSFORME
INVALID
REMIND
LATER
ASSIGNED
VERIFIED
Source: Bugzilla: Lifecycle of a bug

10. @otusweb
Pair programming
A second brain always brings in
more value
Catch default very early in the cycle
Great to work on complex software
issues
Not so great for simple tasks
Great to mentor other or learn from
others

11. @otusweb
Code review
A second pair of eyes always brings value
Great to learn new practice from fellow
developers
Great to spot flows in code
Don’t hesitate to do them in person or follow
up in person
Review every pull request before merging
Not the place for spellcheck, format check etc

12. @otusweb
Automate
your testing
Manual testing is great, slow and painful
to repeat
Use Unit, integration and UI test
UI test: a pain to maintain, automate
only the most important flow
Unit test are easy to maintain, cover as
much as you can
Lots of tools: XCTest, Cucumber,
Appium, EarlGrey

13. @otusweb
Continuous integration
Goal is to release often, if releasing is
hard, then release cycle lengthen
Continuous integration (continuous build
+ automated testing + delivery
automation)
Jenkins, BuddyBuild, bitrise.io, fastlane
and others

14. @otusweb
Static code analysis
Finds issues with your code flow
Reports on code complexity
Multiple tools available (SwiftLint,
OCLint, fauxpas, xCode, Tailor, Danger)
Run it on build and on pull request
Adopt the rules with your team
Enforce a 0 warning merge rule

15. @otusweb
Use crash AND error reporting
What's worse than a crash? A crash
that you don’t know about.
What’s worse than a crash you don’t
know about, an error you don’t know
about.
Install a crash reporting, link it to your
bug database
Install an error reporting, link it to your
bug database
Prioritise issues based on frequency
and impact

16. @otusweb
Test on real devices in context
The real world throws to many curve balls to only test on the simulator (bad
connection, low battery, backgrounding, hardware specificity)
Performance, BLE, wifi devices, camera based app, TouchID can only be tested on
real devices

17. @otusweb
Automate as much
as possible
I’m lazy, I’m sure you are great,
but probably a little lazy too
Add as many of those tools/
process into your build
automation
Make those automation gate
keepers to prevent bad code into
master

18. @otusweb
Questions?
Olivier Destrebecq
@otusweb
olivier@mobdesignapps.fr
http://www.mobdesignapps.fr